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
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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
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
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
(你的题目分子似乎写错项了,有两个是同类项了)
由题意知,2=2+2m+n,则n=-2m, 所以,把n=-2m代入原式,计算得 原式=55/97
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
同类项则相同字母的次数相等
所以2=2+2m+n
2m+n=0
n=-2m
(3m^3-m^2n+3mn^2-6mn^2+9n^3)/(5m^3+3m^2n-6mn^2+9n^3)
=(3m^3+2m^3-12m^3-72m^3)/(5m^3-6m^3-24m^3-72m^3)
=-79m^3/(-97m^3)
=79/97