Question

Factorise 1-2a-2b-3(a+b)²

Answer 1

#. 1-2a-2b-3(a+b)²
=1-2(a+b)-3(a+b)²
let y=a+b
=1-2y-3y²
=1-3y +y-3y ²
=1(1-3y)+y(1-3y)
=(1-3y)(1+y)
put y=a+b
=(1-3a-3b) (1+a+b)