Question

factorize (x-y)^2 -7(x2-y2)+12(x+y)^2

Answer 1

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

let take x-y =a, x+y = b

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

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

a^2-7ab+12b^2

a^2-4ab-3ab+12b^2

a(a-4b)-3b(a-4b)

(a-3b)(a-4b)

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

(x-y-4x-4y)(x-y-3x-3y)

(-3x-5y)(-2x-4y)