Question

factorise (x-y) ^2 - 7(x^2 - y^2) +12(x +y) ^2

Answer 1

(x-y)²-7(x²-y²)+12(x+y)²

=x²+y²-2xy-7x²+7y²+12(x²+y²+2xy)

=-6x²+8y²-2xy+12x²+12y²+24xy

=6x²+20y²+20xy

Answer 2

Answer:

x²+y²-2xy-7x²+7y²+12x²+12y²+24xy

x²-7x²+12x²=6x²

y²+7y²+12y²=20y²

-2xy+24xy=22xy

so, your answer is 6x²+20y²+22xy

hope it helps you!!!