设m和n均不为0,3x^2y^3和-5x^(2+2m+n)y^3是同类项

问题描述:

设m和n均不为0,3x^2y^3和-5x^(2+2m+n)y^3是同类项
求(3m^3-m^2n+3mn^2-6mn^2+9n^3)\(5m^3+3m^2n-6mn^2+9n^3)的值

根据题意有:2+2m+n=2所以2m+n=0所以n=-2m将n=-2m代入(3m^3-m^2n+3mn^2-6mn^2+9n^3)\(5m^3+3m^2n-6mn^2+9n^3)得:(3m^3-m^2n+3mn^2-6mn^2+9n^3)\(5m^3+3m^2n-6mn^2+9n^3)=(-65m^3)/(-97m^3)=65/97(你的题目...