(2x²y-2xy²)-[(-3x²y²+3x²y)+(3x²y_数学解答

(2x²y-2xy²)-[(-3x²y²+3x²y)+(3x²y²-3xy²)]其中x=-1y=2
先化简,再求值

人气：490 ℃　时间：2019-08-17 14:20:26

解答

原式=2x²y-2xy²-(-3x²y²+3x²y+3x²y²-3xy²)
=2x²y-2xy²-(3x²y-3xy²)
=2x²y-2xy²-3x²y+3xy²
=-x²y+xy²
=-2-4
=-6