# NCTB Class 7 Math Chapter Four Exercise 4.1 Solution

NCTB Class 7 Math Chapter Four Exercise 4.1 Solution by Math Expert. Bangladesh Board Class 7 Math Solution Chapter 4.1 “Multiplication & Division of Algebraic Expressions” Exercise 4.1 Solution.

 Board NCTB Class 7 Subject Math Chapter 4 Chapter Name “Multiplication & Division of Algebraic Expressions” Exercise 4.1 Solution

### Exercise:- 4.1

(1) Solution:- (3abx 43a)

= 12a4 b

(2) Solution:- (5xyx 6az)

= 30axyz.

(3) Solution:- (5ax 2X 3ax2 y)

= 15a3 x7 y

(4) Solution:- 8a2 b X (-2b2)

= -16a2 b3

(5) Solution:- (-2abx2) x (10bx3 y z)

= -20ab4 x3 y z

(6) Solution:- (-3p2 q3)x (-6p5 q4 )

= 18 p7q7

(7) Solution:-  (-12m2 a2 x 2) x (-2ma2 x2)

= 24 m3 a4 x5

(8) Solution:-  (7a3 bx5 y2) x (-3x5 y5 a2 b2 )

= – 21a5 b3 x10y5

(9) Solution:- (2x+3y) (5xy)

= (10x2 y +15xy2)

(10) Solution:- (5x- 4xy) (9x y)

= 45x y – 36 x y

(11) Solution:- (2a2 – 3b2+c2) (a3 b2)

= 2a5 b2 – 3a3 b4+ a3 b2 c2

(12) Solution:- (x3 – y2 + 3xyz) (x4 y)

= x7 y- x4 y3 + 3x5 y z

(13) Solution:- (2a-3b) (3a+2b)

= 6a2 + 4ab- 9ab- 6b2

= 6a2 – 5ab- 6b2

(14) Solution:- (a+ b) (a-b)

= a2 –b2

(15) solution:- (x2+1) (x2-1)

= (x2)2 – (11)2

= (x4-1)

(16) Solution:- (a+ b) (a+ b)

= a3+ a2 b+ ab2 +b3

(17) Solution:- (a2 –a b +b2) (a +b)

= a3+ a2 b – a2 b – a b2+ a b2+ b3

= a3+b3

(18) Solution:- (x+2xy+y) 9x+y)

= x3+yx2+2x2 y+2x2 y+ xy2 +y3

= x3+ 3x2 y+ 3xy2+ y3

(19) Solution:- (x2-2xy+y2) (x-y)

= x2-x2 y – 2x2 y+2x y2+xy2-y3

= x3– 3xy2+ 3xy2– y3

(20) Solution:- (x+2x-3) (x+3)

= x3 + 3x2 + 2x2 +6x- 3x-9

= x3 + 5x2+ 3x-9

(21) Solution:- (a2+ab+ b2) (b2– ab+ a2)

= a2 b2 –a3b+a4 +ab3– a2 b2 +a3b+ b4-ab3+a2 b2

= a4+b4+a2 b2

(22) Solution:- (a+ b +c) (a+ b +c)

= (a + b + c)2

= a2+b2+c2+2ab+2bc+2ca

(23) Solution:- (x2-x3y +x2 y2+ x3y- x2 y2 + xy3+ x2 y2 – xy3+y4)

= x4+ x2 y2 +y4

(24) Solution:- (y2-y+1) (1+y+y2)

= (y2+ y3+ y4-y- y2- y3+1+y+ y2)

= y4+ y2+1

(25) Solution:-

A= x2+xy+y2

B= x-y

Therefore, L.H.S, AB

= (x2+xy+y2) (x-y)

= x3 – y3

= R.H.S

L.H.S=R.H.SS (proved).

(26) Solution:- AB.

= (a2-ab+b2) (a+ b)

= a3+b3

(27) Solution:- L.H.S,

(a2+1) (a – 1) (a2+1)

= (a2-1) (a2+1)

= (a2)2 – (1)2

= a4 – 1

= R.H.S

(28) Solution:- L.H.S,

(x +y) (x-y) (x +y)

= (x2-y2) (x2+y2)

= (x2)2 – (y2)2

= x4-y4

= R.H.S

Updated: January 26, 2021 — 7:57 am