Question

化简求值(x+y)(x-y)-(x-y)²-6x²y除2y+(2xy)²除(-4xy)其中x=-2,y=1/3

Answer 1

(x+y)(x-y)-(x-y)²-6x²y除2y+(2xy)²除(-4xy)
=x²-y²-x²+2xy-y²-6x²-xy
=-6x²-2y²+xy

当x=-2,y=1/3
原式=-24-2/9-2/3
=-24又8/9

追问

已知x^m=2,x^n=3，求x^3m+2n的值？

追答

再帮你回答一题，以后采纳后再求助，不要追问新题

x^(3m+2n)
=x^3m×x^2n
=(x^m)³×(x^n)²
=2³×3²
=72

追问

额打错了是减法x^(3m-2n)

追答

x^(3m-2n)
=x^3m/x^2n
=(x^m)³/(x^n)²
=2³/3²
=8/9