Question

factoirse (ii) 4(x - y)2 - 12 (x + y) (x - y) + 9 (x + y)2

Answer 1

let (x-y)=a and (x+)=b

=4a2-12ab+ 9b2

splitting middle trem -12=-6-6 also 4×9=-6×-6

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

=2a(2a-3b)-3b(2a-3b)

=(2a-3b) (2a-3b)

substitute a=x-y and b=x+y

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

=( 2x- 2y-3x-3y)2

=(-x-5y)2

=[(-1) (x+5y)]2

=(x+5y)2