Question

"Question 3 Factorise (i) x^2 + xy + 8x + 8y (ii) 15xy − 6x + 5y − 2 (iii) ax + bx − ay − by (iv) 15pq + 15 + 9q + 25p (v) z − 7 + 7xy − xyz

Class 8 Factorisation Page 220"

Answer 1

Factors:

In a product of two or more expressions each expression is called a factor of the product.

 

Factorization:

The process of writing a given expression as a product of two or more factors is called factorization.

Factorisation by Grouping:

Sometimes the terms of the given expression need to be arranged in suitable groups such that each group has a common factor. we then take out the common factor of all the groups .

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Solution:

i)

x² + x y + 8x + 8y
= x(x+y) + 8(x+y)

=(x+y)(x+8)

2) 15 xy – 6x + 5y – 2
= 3x(5y-2) +1(5y-2)

=(3x+1)(5y-2)

3) ax + bx – ay – by
= x(a+b) –y(a+b)

=(a+b)(x-y)

4) 15 pq + 15 + 9q + 25p
=15pq+9q +25p+15
= 3q(5p+3) + 5(5p+3)

=(3q+5)(5p+3)

5) z – 7 + 7 x y – x y z
=z-xyz-7+7xy
=z(1-xy)-7(1-xy)

=(z-7)(1-xy)

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Hope this will help you....