Question

(a+b)(x+y)-3(a+b)(x-y)分解因式

Answer 1

(a+b)(x+y)-3(a+b)(x-y)
=(a+b)(x+y-3x+3y)
=(a+b)(4y-2x)
=2(a+b)(2y-x)

Answer 2

(a+b)(x+y)-3(a+b)(x-y)
=(a+b)[(x+y)-3(x-y)]
=(a+b)[x+y-3x+3y]
=(a+b)[4y-2x]
=(a+b)[2(2y-x)]
=2(a+b)(2y-x)