求整式-6x²y加上2x³-xy²+7y³的和与-7x²y+2x³-x_数学解答

求整式-6x²y加上2x³-xy²+7y³的和与-7x²y+2x³-xy²-y³的差

人气：404 ℃　时间：2020-02-04 09:51:16

解答

-6x²y+2x³-xy²+7y³-(-7x²y+2x³-xy²-y³)
=-6x²y+2x³-xy²+7y³+7x²y-2x³+xy²+y³
=8y³+x²y