3(2x^2y-xy^2)-(4xy^2+3x^2y)其中x=-1y=2_数学解答

3(2x^2y-xy^2)-(4xy^2+3x^2y)其中x=-1y=2

人气：295 ℃　时间：2020-04-21 06:33:52

解答

解由3(2x^2y-xy^2)-(4xy^2+3x^2y)
=6x^2y-3xy^2-4xy^2-3x^2y
=6x^2y-3x^2y-3xy^2-4xy^2
=3x^2y-7xy^2
=3（-1）^2×2-7（-1）×2^2
=6+28
=34