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)_数学解答

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

人气：328 ℃　时间：2019-10-10 01:13:37

解答

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...