Question

FACTORISE 1-3x-3y-4(x+y)^2

Answer 1

1-3x-3y-4(x+y)²

4-3-3x-3y-4(x+y)²

4(1-(x+y)² )-3(1+x+y)

4(1²-(x+y)² )-3(1+x+y)

4{(1-x-y)(1+x+y)}-3(1+x+y)

(1+x+y) {4(1-x-y)-3}

(1+x+y) {4-4x-4y-3)

⇒ (1+x+y) (1-4x-4y) ....

Answer 2

1-3x-3y-4(x+y)²

=4-3-3x-3y-4(x+y)²

=4(1-(x+y)² )-3(1+x+y)

=4(1²-(x+y)² )-3(1+x+y)

=4{(1-x-y)(1+x+y)}-3(1+x+y)

=(1+x+y) {4(1-x-y)-3}

=(1+x+y) {4-4x-4y-3)

= (1+x+y) (1-4x-4y)