Question

求4-12(x-y)+9(x-y)二次方 因式分解

Answer 1

原式=9(x-y)+12(x-y)+4(把(x-y)看做一个整体)

=[3(x-y)]+223(x-y)+22（公式a+2ab+b=(a+b)）

=[3(x-y)+2]