Rd Sharma Solutions Class 8 Chapter 7 Factorization
Welcome to NCTB Solution. Here with this post we are going to help 8th class students for the Solutions of RD Sharma Class 8 Mathematics, Chapter 7, Factorization. Here students can easily find Exercise wise solution for chapter 7, Factorization. Students will find proper solutions for Exercise 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8 and 7.9 Our teacher’s solved every problem with easily understandable methods so that every students can understand easily.
Factorization Exercise 7.1 Solution :
Question no – (1)
Solution :
Given, 2x² and 12x²
= 2x² = 2 × x × x
12x² = 3 × 2 × 2 × x × x
∴ HCF = 2 × x × x = 2x²
Therefore, the greatest common factor of 2x² and 12x² is 2x².
Question no – (2)
Solution :
Given, 6x³y and 18x²y³
= 6x³y = 2 × 3 × x × x × x × y
= 18x²y³ = 2 × 2 × 3 × x × x × y × y × y
∴ HCF = 2 × 3 × x × x × y = 6x²y
Therefore, Greatest common factor of 6x³y and 18x² y³ is 6x²y
Question no – (5)
Solution :
Given, 12ax², 6a²x³ and 2a³x⁵
12ax² = 3 × 2 × a × x × x
6a²x³ = 3 × 2 × a × a × x × x × x
2a³x⁵ = 2 × a × a × a × x × x × x × x × x
∴ HCF = 2 × a × x × x = 2ax²
Therefore, the greatest common factor of 12ax², 6a²x³ and 2a³x⁵ is 2ax².
Question no – (6)
Solution :
Given, 9x², 15x²y³, 6xy² and 21x²y²
9x² = 3 × 3 × x × x
15x²y³ = 3 × 5 × x × x × y × y × y
6xy² = 3 × 2 × x × y × y × y
21x²y² = 3 × 7 × x × x × y × y
∴ HCF = 3 × x = 3x
Therefore, the greatest common factor of 9x², 15x²y³, 6xy² and 21x²y² is 3x.
Question no – (7)
Solution :
As per the question, 4a²b³, -12a³b, 18a⁴b³
4a²b³ = 2 × 2 × a × a × b × b × b
12a³b = 3 × 2 × 2 × a × a × a × b
18a⁴b³ = 3 × 3 × 2 × a ×a × a × a × b × b × b
∴ HCF = 2 × a × a × b = 2a²b
Therefore, Greatest Common Factor of 4a²b³, -12a³b and 18a⁴b³ is 2a²b
Question no – (8)
Solution :
Given, 6x²y², 9xy³, 3x³y²
6x²y² = 2 × 3 × x × x × y × y
9xy³ = 3 × 3 × x × y × y × y
3x³y² = 3 × x × x × x × y × y
∴ HCF = 3 × x × y × y × = 3xy²
Therefore, Greatest common factor of 6x²y², 9xy³ and 3x³y² is 3xy²
Question no – (9)
Solution :
Given, a²b³ and a³b²
a²b³ = a × a × b × b × b
a³b² = a × a × a × b × b
∴ HCF = a × a × b × b = a²b²
Therefore, Greatest Common Factor of a²b³ and a³b² is a²b²
Question no – (10)
Solution :
Given, 36a²b²c⁴, 54a⁵c², 90a⁴b²c²
36a²b²c⁴ = 2 × 2 × 3 × 3 × a × a × b × b × c × c × c × c
54a⁵c² = 2 × 3 × 3 × 3 × a × a × a × a × a × c × c
90a⁴b²c² = 2 × 3 × 3 × 5 × a × a × a × a × b × b × c × c
∴ HCF = 2 × 3 × 3 × a × a × c × c = 18a²c²
∴ The greatest common factor of 36a²b²c⁴, 54a⁵c² and 90a⁴b²c² is 18a²c²
Question no – (11)
Solution :
Given, x³ and -yx²
x³ = x × x × x
-yx² = y × x × x
∴ HCF = x × x = x²
∴ The greatest common factor of x³ and – yx² is x²
Question no – (12)
Solution :
Given, 15a³, -54a², -150a
15a³ = 3 × 5 × a × a × a
-45a² = 3 × 3 × 5 × a × a
– 150a = 3 × 5 × 2 × 5 × a
∴ HCF = 3 × 5 × a = 15a
Therefore, the Greatest Common Factor of 15a³, -45a² and -150a is 15a
Question no – (13)
Solution :
Given, 2x³y², 10x²y³, 14xy
2x³y² = 2 × x × x × x × y × y
10x²y³ = 2 × 5 × x × x × y × y × y
14xy = 2 × 7 × x × y
∴ HCF = 2 × x × y = 2xy
Therefore, Greatest Common Factor of 2x³y², 10x²y³ and 14xy is 2xy.
Question no – (14)
Solution :
Given, 14x³y⁵, 10x⁵ y³, 2x²y²
14x³y⁵ = 2 × 7 × x × x × x × y × y × y × y× y
10x⁵y³ = 2 × 5 × x × x × x × x × x × y × y × y
2x²y² = 2 × x × x × y× y
∴ HCF = 2 × x × x × y × y = 2x²y²
Therefore, the Greatest Common Factor of 14x³y⁵, 10x⁵ y³ and 2x²y² is 2x²y²
Question no – (15)
Solution :
5a⁴ + 10a³ – 15a²
= 5 × a × a × a × a + 2 × 5 × a × a × a – 3 × 5 × a × a
= 5a² (a² + 2a – 3)
∴ The Greatest Common Factor will be 5a²
Question no – (16)
Solution :
Given, 2xyz + 3x²y + 4y²
= 2 × x × y × z + 3 × x × x × y + 2 × 2 × y × y
= y (2xz + 3x² + 4y)
∴ The Greatest Common Factor is y
Question no – (17)
Solution :
Given, 3a²b² + 4b²c² + 12a²b²c²
= 3 × a × a × b × b + 4 × b × b × c × c + 3 × 4 × a × a × b × b × c × c
= b² (3a²+ 4c² + 12a²c²)
∴ The Greatest Common Factor of the given number b²
Factorization Exercise 7.2 Solution :
Question no – (1)
Solution :
Given, 3x – 9
= 3x – 3²
∴ 3 (x – 3)
Question no – (2)
Solution :
Given, 5x – 15x²
∴ 5x (1 – 3x)
Question no – (3)
Solution :
Given, 20a^12b² – 15a⁸b⁴
∴ 5a³b² (4a⁴- 3b²)
Question no – (4)
Solution :
Given, 72x⁶y⁷ – 96x⁷y⁶
∴ 24x⁶y⁶ (3y – 4x)
Question no – (5)
Solution :
Given, 20x³ – 40² + 80x
∴ 20x (x² – 2² + 4)
Question no – (6)
Solution :
Given, 2x³y² – 4x²y³ + 8xy⁴
∴ 2xy² (x – 2xy + 4y²)
Question no – (7)
Solution :
Given, 10m³n² +15m⁴n – 20m²n³
∴ 5m²n (2mn+3m² – 4n²)
Question no – (8)
Solution :
Given, 2a⁴b⁴ – 3a³b⁵ – 4a²b⁵
∴ a²b⁴ (2a² – 3ab + 4b)
Question no – (9)
Solution :
Given, 28a² + 14a²b² – 21a⁴
∴ 7a² (a + 2b² – 3a²)
Question no – (10)
Solution :
Given, a⁴ b – 3a²b² – 6ab³
∴ ab (a³ – 3ab – 6b²)
Question no – (11)
Solution :
Given, 2l²mn – 3lm²n + 4lmn²
∴ lmn (2l – 3m + 4n)
Question no – (12)
Solution :
Given, x⁴y² – x²y⁴ – x⁴y⁴
∴ x²y² (x² – y² – x²y²)
Question no – (13)
Solution :
Given, 9x²y + 3axy
∴ 3xy (3x + a)
Question no – (14)
Solution :
Given, 16m – 4m²
∴ 4m (4 – m)
Question no – (15)
Solution :
Given, – 4a² – 4ab – 4ca
∴ – 4a (a – b + c)
Question no – (16)
Solution :
Given, x²yz + xy²z + xyz²
∴ xyz (x+ y+ z)
Question no – (17)
Solution :
Given, ax²y + bxy² + cxyz
∴ xy (ax + by + cz)
Factorization Exercise 7.3 Solution :
Question no – (1)
Solution :
Give, 6x (2x-y) + 7y (2x-y)
∴ (2x – b) (6x + 7y)
Question no – (2)
Solution :
Given, 2r(y – x) + s (x – y)
= 2r(b – x) – s (y – x)
∴ (y – x) (2r – s)
Question no – (3)
Solution :
Given, 7a(2x – 3) + 3b (2x – 3)
∴ (2x + 3) (7a + 3b)
Question no – (4)
Solution :
Given, – 9a (6a – 5b) – 12a²(6a – 5b)
= (6a – 5b) (9a – 12a²)
∴ 3a(3 – 4a) (6a – 5b)
Question no – (5)
Solution :
Given, 5(x – 2y)² + 3 (x – 2y)
= (x – 2y) [(x – 2y) 5 + 3]
∴ (x – 2y) (5x – 10y + 3)
Question no – (6)
Solution :
Given, 16(2l – 3m) ² – 12(3m – 2l)
= 16 (2l – 3m) ² + 12 (2l – 3m)
= 4 (2l – 3m) [4 (2l – 3m) + 3]
∴ 4 (2l – 3m) (8l – 12m + 3)
Question no – (7)
Solution :
Given, 3a (x – 2y) – b (x – 2y)
∴ (x – 2y) (3a – b)
Question no – (8)
Solution :
Given, a²(x + y) + b²(x + y) + c²(x + y)
∴ (x + y) (a² + b² + c²)
Question no – (9)
Solution :
Given, (x – y)² + (x – y)
∴ (x – y) (x – y + 1)
Question no – (10)
Solution :
Given, 6 (a + 2b) – 4 (a² + 2b) ²
= 2 (a + 2b) (3 – 2 (a + 2b))
∴ 2 (a + 2b) (3 – 2a – 4b)
Question no – (11)
Solution :
Given, a (x – y) + 2b(y – x) + c(x – y)²
= a (x – y) – 2b (x – y) + c (x – y)²
= (x – y) [a – 2b + c (x – y)]
∴ (x – y) (a – 2b) + (cx – cy)
Question no – (12)
Solution :
Given, – 4 (x – 2y)² + 8(x – 2y)
∴ – 4 (x – 2y) (x – 2y – 2)
Question no – (13)
Solution :
Given, x³(a – 2b) + x²(a – 2b)
∴ x²(a – 2b) (x + 1)
Question no – (14)
Solution :
Given, (2x – 3y) (a + b) + (3x – 2y) (a + b)
= (a + b) (2x – 3y + 3x – 2y)
= (a + b) (5x – 5y)
∴ 5 (x + y) (a + b)
Question no – (15)
Solution :
Given, 4(x + y) (3a – b) + 6 (x + y) (2b – 3a)
= 2(x + y) [2 (3a – b) + 3 (2b – 3a)]
= 2(x + y) (6a – 2b + 6b – 9a)
∴ 2(x + y) (4b – 3a)
Factorization Exercise 7.4 Solution :
Question no – (1)
Solution :
Given, qr – pr + qs – ps
= r(q – p) + s(q – p)
∴ (q – p) (r + s)
Question no – (2)
Solution :
Given, p²q – pr² – pq + r²
= p (q p – r²) – 1 (p q- r²)
∴ (pq – r²) (p – 1)
Question no – (3)
Solution :
Given, 1 + x + xy + x²y
= xy (x + 1) + 1(x + 1)
∴ (x + 1) (xy + 1)
Question no – (4)
Solution :
Given, ax + ay – b x – by
= a(x + y) – b(x + y)
∴ (x + y) (a – b)
Question no – (6)
Solution :
Given, x² + xy + xz + yz
= x(x+ y) + z(x + y)
∴ (x + y) (x + z)
Question no – (7)
Solution :
Given, 2ax + bx + 2ay + by
= x(2a + b) + y(2a + b)
∴ (2a + b) (x + y)
Question no – (8)
Solution :
Given, ab – by – ay + y²
= b(a – y) – y(a – y)
∴ (a – y) (b – y)
Question no – (9)
Solution :
Given, axy + bcxy – az – bcz
= axy – az + bcxy – bcz
= a(xy – z) + bc(xy – z)
∴ (xy – z) (a + bc)
Question no – (10)
Solution :
Given, 2l²mn – 3lm²n + 4lmn²
∴ lmn (2l – 3m + 4n)
Question no – (11)
Solution :
Given, x³ – y² +x – x²y²
= x³ + x – y² – x²y²
= x(x² + 1) – y²(x² + 1)
∴ (x² + 1) (x – y²)
Question no – (12)
Solution :
Given, 6xy + 6 – 9y – 4x
= 6xy – 4x + 6 – 9
= 2x (3y – 2) – 3 (3y – 2)
∴ (3y – 2) (2x – 3)
Question no – (13)
Solution :
Given, x² – 2ax – 2ab + bx
= x (x – 2a) – b(x – 2a)
∴ (x – 2a) (x – b)
Question no – (14)
Solution :
Given, x³ – 2x²y + 3xy² – 6y³
= x³ + 3xy² – 2x²y – 6y³
= x (x² + 3y) – 2y (x² + 3y²)
∴ (x – 2y) (x² + 3y²)
Question no – (15)
Solution :
Given, abx² + (ay – b) x – y
= abx² + ayx – bx – y
= ax (bx+ y) -1 (bx + y)
∴ (bx + y) (ax – 1)
Question no – (16)
Solution :
Given, a²x² + 2abxy + b²y² + b²y² – 2abxy + a²y²
= a²x² + b²x² + b²y + a²y²
= x² (a² + b²) + y² (a² + b²)
∴ (x² + y²) (a² + b²)
Question no – (17)
Solution :
Given, 16 (a – b)³ – 24 (a – b)²
= 8 (a – b)² [2 (a – b) – 3]
∴ 8 (a – b)² (2a – 2b – 3)
Question no – (18)
Solution :
Given, ab (x² + 1) + x(a² + b²)
= abx² + a b +a²x + b²x
= abx² + a²x + ab + b²
= ax(bx + a) + b (bx + a)
∴ (bx + a) (ax + b)
Question no – (19)
Solution :
Given, a²x² + (ax² + 1) x + a
= a²x² + ax³ + x + a
= ax² (a + x) + 1 (a + x)
∴ (a + x) (ax² + 1)
Question no – (20)
Solution :
Given, a (a – 2b – c) 2bc
= a² – 2ab – ac + 2bc
= a (a – 2b) – c (a – 2b)
∴ (a – 2b) (a – c)
Question no – (21)
Solution :
a (a + b – c) – bc
= a² +ab – ac – bc
= a(a+ b) – c (a + b)
∴ (a + b) (a – c)
Question no – (22)
Solution :
Given, x² – 11xy – x + 11y
= x(x – 11y) – 1(x – 11y)
∴ (x – 11y) (x – 1)
Question no – (23)
Solution :
Given, ab – a – b +1
= a (b – 1) – 1 (b – 1)
∴ (b – 1) (a – 1)
Question no – (24)
Solution :
Given, 1 + x + xy + x²y
= xy (x + 1) + 1(x + 1)
∴ (x + 1) (xy + 1)
Factorization Exercise 7.5 Solution :
Question no – (1)
Solution :
Given, 16x² – 25y²
= (4x)² – (5y)²
∴ (4x + 5y) (4x – 5y)
Question no – (2)
Solution :
Given, 27x² – 12y²
= 3(9x² – 4y²)
= 3[(3x) ² – (2y) ² ]
∴ 3[(3x + 2y) (2x – 2y)
Question no – (3)
Solution :
Given, 144a² – 289b²
= (12a)² – (17b)²
∴ 12a + 17b) (12a – 17b)
Question no – (4)
Solution :
Given, 12m² – 27
= 3 (4m² – 9)
= 3 [ (2m)² – 3²]
∴ 3 (2m + 9) (2m – 9)
Question no – (5)
Solution :
Given, 125x² – 45y²
= 5 (25x² – 9y²)
= 5 [(5x)² – (3y)²]
∴ 5 (5x + 3y) (5x – 3y)
Question no – (6)
Solution :
Given, 144a² – 169b²
= (12a)² – (13b)²
∴ (12a + 13b) (12a – 13b)
Question no – (7)
Solution :
Given, (2a – b)² – 16c
= (2a -b)² – (4c)²
∴ (2a – b + 4c) (2a – b – 4c)
Question no – (8)
Solution :
Given, (x + 2y)² – 4 (2x – y)²
= x² + 2xy + 4y² – 4(4x² – 2xy +y²)
∴ x² + 2xy + 4y² – 16x²
Question no – (9)
Solution :
Given, 3a⁵ – 48a³
= 3a³ (a² – 16)
= a² – 4²
∴ (a + 4 ) (a – 4)
Question no – (10)
Solution :
Given, a⁴ – 16b⁴
= (a²)² – (4v²)² = (a² + 4b²)
= (a² + 4b²) [a² – (2b) ² ]
∴ (a² + 4b²) (a² + 2b) (a² – 2b)
Question no – (11)
Solution :
Given, x⁸ – 1
= (x⁴)² – 1² = (x⁴ + 1) (x⁴ – 1)
= (x⁴ +1) [(x⁴)⁴ – 1⁴]
= (x⁴ +1) (x² +1) (x² – 1)
= (x⁴ +1) (x² +1) (x² -1)
∴ (x² +1) (x² + 1) (x + 1) (x – 1)
Question no – (12)
Solution :
Given, 64 – (a + 1)²
= 8² – (a + 1)²
= (8 + a + 1) (8 – a – 1)
∴ (a + 9) (7 – a)
Question no – (13)
Solution :
Given, 36l² 36l² – (m+ n)²
= (6l) ² – (m +n)²
= (6l + m + n) (6l – m -n) (m+ n)²
= (6l) ² – (m +n)²
∴ (6l + m + n) (6l – m -n)
Question no – (14)
Solution :
Given, 25x⁴ y⁴ – 1
= (5x²y²)² – 1
∴ (5x²y² + 1) (5x²y² – 1)
Question no – (15)
Solution :
Given, a⁴ – 1/b⁴
= (a²)² – (1/b²)²
= (a² + 1/b²) (a² – 1/b²)
∴ (a² + 1/b²) (a + 1/b) (a – 1/b)
Question no – (16)
Solution :
Given, x³ – 144x
= x (x² – 144)
= x (x² – 12²)
∴ x (x + 12) (x – 12)
Question no – (18)
Solution :
Given, 9 (a – b)² – 100(x -y)²
= [3 (ab)]² – [10 (x – y)]²
∴ [3 (a – b) + 10(x – y) ] [3 (a-b) – 10 (x – y)]
Question no – (19)
Solution :
Given, (3 + 2a)² – 25a²
= (3 + 2a)² – (5a)²
= ( 3 + 2a + 5a) (3 + 2a – 5a)
∴ (3 + 7a) (3 – 3a)
Question no – (20)
Solution :
Given, (x + y)² – (a – b)²
∴ (x+ y + a – b) (x + y – a + b)
Question no – (21)
Solution :
Given, 1/16x²y² – 4/49y²z²
= (4/1xy)² – (2/7yz) ²
∴ (1/4xy + 2/7yz) (1/4xy – 2/7yz)
Question no – (22)
Solution :
Given, 75a³b² – 108ab⁴
= 3ab² (25²a – 36b²)
= 3ab² [(5a)² – (6b)²]
∴ 3ab² (5a + 6b) (5a – 6b)
Question no – (23)
Solution :
Given, x⁵ – 16x³
= x³ (x² – 16)
= x³ (x² – 4²)
= x³ (x² + 4) (x² – 4)
= x³ (x² + 4) (x² + 2²)
∴ x³ (x + 2) (x – 2)
Question no – (24)
Solution :
Given, 50/x² – 2x²/81
= 2 (25/x² – x²/81)
= 2 [(5/x)² – (x/9)²]
∴ 2 (5/x + x/9) (5/x – x/9)
Question no – (28)
Solution :
Given, p²q² – p⁴q⁴
= (pq)² – (p²q²)
= p²q² (1- p²q²)
= p² q² [(1² – (pq)²]
∴ p²q² (1 + pq) (1 – p q)
Question no – (30)
Solution :
Given, a⁴b⁴ – 16c⁴
= (a²b²) – (4c)²
= (a²b² + 4c²) (a²b²- 4c²)
= (a²b² + 4c²) [(ab)² – (2c)² ]
∴ (a²b² + 4c²) (ab + 2c) (ab – 2c)
Question no – (31)
Solution :
Given, x⁴ – 625
= (x²)² – (25)²
= (x² +25) (x² – 25)
= (x² + 25) (x² – 5²)
∴ (x² + 25) (x + 5) (x – 5)
Question no – (32)
Solution :
Given, x⁴ – 1
= (x²)² – 1²
= (x² + 1) (x² – 1)
= (x² + 1) (x² – 1²)
∴ (x² + 1) (x + 1) (x – 1)
Question no – (34)
Solution :
Given, x – y – x² + y²
= x – y -(x² – y²)
= (x – y) – (x + y) (x – y)
∴ (x – y) (1 – x + y)
Question no – (35)
Solution :
Given, 16 (2x – 1)² – 25y²
= [4(2x – 1)]² – (5y)²
= [4(2x – 1) + 5y)] [4(2x – 1) – 5y]
∴ (8x – 4 + 5y) (8x – 4 – 5y)
Question no – (37)
Solution :
Given, (2x + 1)² – 9x⁴
= (2x + 1)²- (3x²)²
∴ (2x +1 + 3x²) (2x + 1 – 3x²)
Question no – (38)
Solution :
Given, = x⁴ + (2y – 3z)
= (x²) – (2y – 3z)²
∴ (x² + 2y – 3z) (x² – 2y + 3z)
Question no – (39)
Solution :
Given, a² – b² + a – b
= (a² – b²) + (a – b)
= (a + b) (a – b) + (a + b)
∴ (a – b) (a + b + 1)
Question no – (40)
Solution :
Given, 16a⁴ – b⁴
= (4a²) – (b²)
= (4a² + b²) (4a² – b²)
= (4a² + b²) [(2a)² – b²]
∴ (4a² + b²) (2a + b) (2a – b)
Question no – (42)
Solution :
Given, 2a⁵ – 32a
= 2a (2a⁴ – 160
= 2a [a²) – 4²]
= 2a (a² +4) (a² -4)
= 2a (a² +4) (a² – 2²)
∴ 2a (a² + 4) (a + 2) (a – b)
Question no – (43)
Solution :
As per the question, a⁴b⁴ – 81c⁴
= (a²b²)² – (9c²)
= (a² b² + 9c²) (a² b² – 9c²)
= (a² b² +9c²) [(ab) ² – (3c) ²]
∴ (a² b² + 9c²) (ab + 3c) (ab – 3c)
Question no – (44)
Solution :
Given, xy⁹ – yx⁹
= xy (y⁸ – x⁸) = xy [(y⁴)² – (x⁴)²]
= xy (y⁴ + x⁴) (y⁴ – x⁴)
= xy (y⁴ + x⁴) (y⁴ + x⁴) [(y²)² – (x²)²]
= xy (y⁴ + x⁴) (y² + x²) (y² – x²)
∴ xy (y⁴ + x⁴) (y² – x²) (y + x) (y – x)
Question no – (45)
Solution :
Given, x³ – x
= x (x² – 1)
= x (x² – 1²)
∴ x (x + 1) (x – 1)
Question no – (46)
Solution :
Given, 18a²x² – 32
= 2 (9a²x² – 16)
= 2 [(3ax)² – 4²]
∴ 2 [3ax +4] [3ax – 4)]
Factorization Exercise 7.6 Solution :
Question no – (2)
Solution :
Given, 9a² – 24ab + 16b²
= (3a) ² – 2. 3a. 4b + (4b)²
= (3a – 4b)²
∴ (3a – 4b) (3a – 4b)
Question no – (3)
Solution :
Given in the question, p²q² – 6pqr + 9r²
= (pq)² – 2 . p q. 3r + (3r)²
= (pq – 3r)²
∴ (pq – 3r) (pq – 3r)
Question no – (5)
Solution :
Given, a² + 2ab + b² – 16
= (a + b)² – 4²
∴ (a + b + 4) (a + b – 4)
Question no – (6)
Solution :
Given, 9z² – x² + 4xy – 4y²
= (3z)² – [x² – 2. x 2y + (2y)²]
= (3z)² – (x – 2y) ²
∴ (3z + x – 2y) (3z – x + 2y)
Question no – (8)
Solution :
As per the question, 16 – a⁶ + 4a³ b³ – 4b⁶
= 4² – [(a³)²- 2. a³ 2b² + (2b³)²]
= 4² – (a³ + 2b³)²
∴ (4 + a³ + 2b³) (4 – a³ – 2b³)
Question no – (9)
Solution :
Given, a² – 2ab + b² – c²
= (a – b)²c²
∴ (a – b + c) (a – b – c)
Question no – (10)
Solution :
Given, x² + 2x + 1 – 9y²
= (x + 1)² – (3y)²
∴ (x + 1 + 3y) (x + 1 – 3y)
Question no – (11)
Solution :
Given, in the question, a² + 4ab + 3b²
= a² + 4ab + 4b² – b²
= a² + 2. a. 2b + (2b)² – b²
= (a + 2b)² – b²
= (a + 2b + b) (a + 2b – b)
∴ (a + 3b) (a + b)
Question no – (12)
Solution :
Given, 96 – 4x – x²
= 100 – 4 – 4x – x²
= (10)² – (2² + 2.2.x + x²)
= (10)² – (2 + x) ²
= (10 + 2 + x) (10 – 2 + x)
∴ (12 + x) (8 + x)
Question no – (13)
Solution :
Given, a⁴ + 3a² + 4
= a⁴ + 4a² + 4 – a²
= [(a²)² + 2 . a² . 2 + (2)²] – a²
= (a² + 2) – a²
∴ (a² + 2 + a) (a² + 2 – a)
Question no – (17)
Solution :
Given, 25 – p² – q² – 2pq
= 5² – (p² + 2pq + q²)
= 5² – (p + q) ²
∴ (5 + p + q) (5 – p – q)
Question no – (18)
Solution :
Given, x² + 9y² – 6xy – 25a²
= [x² – 2. x .3y + (3y)²] -(5a)²
= (x – 3y)² – (5a) ²
∴ (x – 3y + 5a) (x – 3y – 5a)
Question no – (19)
Solution :
Given, 49 – a² + 8ab – 16b²
= 7² – (a² – 82. a. 4b + 4b²)
= 7² – (a – 4b)²
∴ (7 + a – 4b) (7 – a + 4b)
Question no – (20)
Solution :
As per the question, a² – 8ab + 16b² – 25c²
= [a² – 2a. a .4b + (4b)²] – (5c)²
= (a – 4b)² – (5c)²
∴ (a – 4b + 5c) (a – 4b – 5c)
Question no – (21)
Solution :
Given, x² – y² + 6y – 9
= x² – (y² – 2.y.3 + 3²)
= x² – (y – 3) ²
∴ (x + y – 3) (x – y + 3)
Question no – (22)
Solution :
Given, 25x² – 10x + 1 – 36y²
= [(5x)² – 2. 5x. 1+ 1²] – (6y)²
= (5x + 1)² – (6y)²
= (5x + 1)² – (6y)² (5x + 16y)
∴ (5x + 1 + 6y) (5x + 1 – 6y)
Question no – (23)
Solution :
Given, a² – b² + 2bc – c²
= a² – (b² – 2bc + c²)
= a² – (b – c)²
∴ (a + b – c) (a – b + c)
Question no – (24)
Solution :
Given, a² + 2ab + b² – c²
= (a + b)² – c²
∴ (a + b + c) (a + b – c)
Question no – (25)
Solution :
Given, in the question, 49 – x² – y² + 2xy
= 7² – (x² – 2xy + y²)
= 7² – (x – y) ²
∴ (7 + x – y) (7 – x + y)
Question no – (26)
Solution :
Given in the question, a² + 4b² – 4ab – 4c²
= [a² – 2. a. 2b + (2b)²] – (2c)²
= (a – 2b)² – (2c)²
∴ (a – 2b + 2c) (a – 2b – 2c)
Question no – (27)
Solution :
Given, x² – y² – 4xz + 4z²
= [x² – z. x. z + (2z)²]
= (x – 2z)² – y²
∴ (x – 2z + y) (x – 2z – y)
Factorization Exercise 7.7 Solution :
Question no – (2)
Solution :
As per the question, 40 + 3x – x²
= 40 + (8 – 5) x – x²
= 40 + 8x – 5x – x²
= 8(x + 5) – x (x + 5)
∴ (x + 5) (8 – x)
Question no – (3)
Solution :
As per given question, a² – 3a – 88
= a² + (11 – 8) a – 88
= a² + 11a – 8a – 88
= a (a + 11) – 8 (a + 11)
∴ (a + 11) (a – 8)
Question no – (4)
Solution :
Given, a² – 14a – 51
= a² – 2. a .7 + 7² – 7² – 51
= (a – 7)² – 49 – 51
= (a – 7)² – 100 = (a – 7)² – (10)²
= (a – 7 + 10) (a – 7 – 10)
∴ (a + 3) (a – 17)
Question no – (5)
Solution :
Given, x² + 14x + 45
= x² + (9 + 5)x + 45
= x² + 9x + 5x + 45
= x (x + 9) + 5(x + 9)
∴ (x + 9) (x + 5)
Question no – (7)
Solution :
x² – 11x – 42
= x² – (14 – 3) x – 42
= x² – 14x + 3x – 42
= x (x – 14) + 3 (x – 14)
∴ (x – 14) (x + 3)
Question no – (8)
Solution :
Given, a²+ 2a – 3
= a² + (3 – 1) a – 3
= a² + 3a – a – 3
= a(a +3) – 1 (a + 3)
∴ (a+ 3) (a – 1)
Question no – (9)
Solution :
Given, a² + 14a + 48
= a² + (8 + 6)a + 48
= a² + 8a + 6a + 48
= a(a + 8) + 6(a + 8)
∴ (a + 8) (a + 6)
Question no – (10)
Solution :
Given, x² – 4x – 21
= x² – (7 – 3) x – 21
= x² – 7x + 3x – 21
= x(x – 7) + 3 (x – 7)
∴ (x – 7) (x + 3)
Question no – (11)
Solution :
Given, y² + 5y – 36
= y² (9 – 4)y – 36
=- y² + 9y – 4y – 36
= y(y + 9) – 4(y + 9)
∴ (y + 9) (y – 4)
Question no – (12)
Solution :
Given, (a² – 5a)² – 36
= (a² – 3a – 2a + 6) (a² – 6a + a – 6)
= a(a – 3) – 2 (a – 3) a(a – 6) + 1 (a – 6)
∴ (a – 3) (a – 2) (a – 6) (a + 1)
Question no – (13)
Solution :
As per the question, (a + 7) (a – 10) + 16
= a² – 10 a + 7a – 70 + 16
= a² – 3a – 54
= a² – 9a + 6a – 54
= a (a – 9) + 6(a – 9)
∴ (a – 9) (a + 6)
Factorization Exercise 7.8 Solution :
Question no – (1)
Solution :
Given, 2x² – 3x – 2
= 2x² – 4x + x – 2
= 2x(x – 2) + 1(x – 2)
∴ (2x + 1) (x – 2)
Question no – (3)
Solution :
Given, 3x² + 10x + 3
= 3x² + 9x + x + 3
= 3x(x + 3) + 1(x + 3)
∴ (x + 3) (3x + 1)
Question no – (4)
Solution :
Given, 7x – 6 – 2x²
= – 2x² + 7x – 6
= – 2x² + 3x + 4x – 6
= – x(2x – 3) + 2(2x – 3)
∴ (2x – 3) (2 – x)
Question no – (5)
Solution :
7x² – 19x – 6
= 7x² – 21x + 2x – 6
= 7x (x – 3) + 2 (x – 3)
∴ (x – 3) (7x + 2)
Question no – (6)
Solution :
As per the question, 28 – 31x + 5x²
= 28 – 4x + 35x – 5x²
= 4 (7 – x) + 5x (7 – x)
∴ (7x – x) (4 + 5x)
Question no – (7)
Solution :
Given, 3 + 23y – 8y²
= 3 – y + 24y – 8y²
= -8y² + 24y – y + 3
= -8y (y – 3) – 1 (y – 3)
∴ (y – 3) (1 – 8y)
Question no – (8)
Solution :
Given, 11x² – 54x + 63
= 11x² – 33x – 21x + 63
= 11x(x – 3) – 21(x – 3)
∴ (x – 3) (11x – 21)
Question no – (9)
Solution :
7x – 6x² + 20
= -6x² + 7x + 20
= -6x² – 15 + 8x +20
= – 6x² – 8x + 15x + 20
= – 2x(3x + 4) + 5(3x + 4)
∴ (3x + 4) (5 – 2x)
Question no – (10)
Solution :
3x² + 22x + 35
= 3x² + 15x + 7x + 35
= 3x (x + 5) + 7(x + 5)
∴ (x + 5) (3x + 7)
Question no – (11)
Solution :
Given, 12x² – 17xy + 6y²
= 12x² – 9xy – 8xy + 6y²
= 3x (4x – 3y) – 2y (4x – 3y)
∴ (4x – 3y) (3x – 2y)
Question no – (12)
Solution :
Given in the question, 6x² – 5xy – 6y²
= 6x² – 9xy + 4xy – 6y²
= 3x (2x – 3y) + 2y (2x – 3y)
∴ (2x – 3y) (3x + 2y)
Question no – (13)
Solution :
Given, 6x² – 13xy + 2y²
= 6x² – 12xy – x y + 2y²
= 6x(x – 2y) + y(x – 2y)
∴ (x – 2y) (6x + y)
Question no – (14)
Solution :
Given, 14x² – 13xy + 15y²
= 14x² + 21xy – 10xy – 15y²
= 7x(2x + 3y) – 5y(2x+ 3y)
∴ (2x + 3y) (7x – 5y)
Question no – (15)
Solution :
6a² + 17ab – 3b²
= 6a² – 18ab + ab – 3b²
= 6a (a – 3b) + b(a – 3b)
= (a – 3b) (6a + b)
Question no – (16)
Solution :
Given, 36a² + 12abc – 15b²c²
= 36a² – 18abc + 30abc – 15b²c²
= 18a (2a – bc) + 15bc (2a – bc)
= (18a- 15bc) (2a – bc)
∴ 3 (6a – 5bc) (2a – bc)
Question no – (17)
Solution :
Given, 15x² – 16xyz – 15y²z²
= 15x² – 25xyz + 9xyz – 15y²z²
= 5x (83x – 5yz) + 3yz (3x – 5yz)
∴ (5x + 3yz) (3x – 5yz)
Question no – (18)
Solution :
(x – 2y) ² – 5 (x – 2y) + 6
Let, (x – 2y) = a
= a² – 5a + 6
= a² – 3a – 2a + 6
= a (a – 3) – 2 (a – 3)
= (a – 3) (a – 2)
= (x – 2y – 3) (x – 2y – 2)
Question no – (18)
Solution :
Given, (2a – b)² + 2 (2a – b) – 8
Let, (2a – b) = x
∴ x² + 2 x – 8
= a² + 4 – 2x – 8
= x (x + 4) – 2 (x + 4)
= (x + 4) (x – 2)
= (2a – b + 4) (2a – b – 2)
[∴ x = (2a – b)]
Question no – (19)
Solution :
Given, x² + 5x + 3
= 2x² + 3x + 2x +3
= x(2x +3) + 1(2x + 3)
∴ (x + 1) (2x + 3)
Factorization Exercise 7.9 Solution :
Question no – (1)
Solution :
Given, p² + 6p + 8
= p² + 4p + 2p + 8
= p(p + 4) + 2(p + 4)
∴ (p + 4) (p + 2)
Question no – (2)
Solution :
Given, q² – 10q + 21
= q² – 7q – 3q + 21
= q(q – 7) – 3(q – 7)
∴ (q – 7) (q – 3)
Question no – (3)
Solution :
Given, 4y² + 12y + 5
= 4 (y² + 3y 5/4)
= 4 [(y² + 2. 1/2. 3y + (1/2) ² + 5/4]
= 4 [( y+ 1/2 )² – 4/4]
= 4 [(y + 1/2) – 1² ]
= 4 [y + 1/2 + 1] [ y + 1/2 -1]
= 4 [2y + 1 + 2/2] [2y + 1 – 2/2]
= 2 [(2y + 3) (2y – 1)
∴ (4y + 6) (4y – 2)
Question no – (4)
Solution :
Given, p² + 6p – 16
= p² + 2. p. 3 + 3v – 3² – 16
= (p + 3)² – 9 – 16
= (p + 3) ² – 25
= (p + 3) ² – 5²
= (p + 3 + 5) (p + 3 – 5)
∴ (p + 8) (p – 2)
Question no – (5)
Solution :
Given, x² + 12x + 20
= x²+ 2. 2. x. 6 + 6² – 6² – 20
= (x + 6)² – 36 – 20
= (x + 6)² – 16
= (x + 6)² – 4²
= (x + 6 + 4) (x + 6 – 4)
∴ (x + 10) (x + 2)
Question no – (6)
Solution :
Given, a² – 14a – 51
= a² – 2. a .7 + 7² – 7² – 51
= (a – 7)² – 49 – 51
= (a – 7)² – 100 = (a – 7)² – (10)²
= (a – 7 + 10) (a – 7 – 10)
∴ (a + 3) (a – 17)
Question no – (7)
Solution :
Given, a²+ 2a – 3
= a² + (3 – 1) a – 3
= a² + 3a – a – 3
= a(a +3) – 1 (a + 3)
∴ (a+ 3) (a – 1)
Question no – (10)
Solution :
Given, z² – 4z – 12
= z² – 2.z.2 + 2² – 2² – 12
= (z – 2)² – 4 – 12
= (z – 2)² – 16
= (z – 2)² – 4²
= (z – 2 + 4) (z – 2 – 4)
∴ (z + 2) (z – 6)
Next Chapter Solution :
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