(1)2x²-y²+(2y²-x²)-(x²+2y²)
=2x²-y²+2y²-x²-x²-2y²
=-y²
=-9
(2)5(3x²y-xy²)-(xy²-3x²y)
=6(3x²y-xy²)
=6xy(3x-y)
=-3(3/2+1)
=-15/2
很高兴为你答疑,
(1)2x²-y²+(2y²-x²)-(x²+2y²)
=2x²-y²+2y²-x²-x²-2y²
=-y²
=-9
(2)5(3x²y-xy²)-(xy²-3x²y)
=6(3x²y-xy²)
=6xy(3x-y)
=-3(3/2+1)
=-15/2
很高兴为你答疑,