-4x²y-8xy²+2x²y-3xy²

-4x²y-8xy²+2x²y-3xy²
-4x²y-8xy²+2x²y-3xy²

-4x²y-8xy²+2x²y-3xy²
-4x²y-8xy²+2x²y-3xy²
=-2x²y-11xy²

4x²y-8xy²+2x²y-3xy²
=-2x²y-11xy²
朋友你是完成百度任务的吧，要不这种你怎么会不会做呢？

-4x²y-8xy²+2x²y-3xy²＝xy(-4x-8y+2x-3y)