先化简,再求值.3m+4n-[2m+(5m-2n)-3n],其中m=1/n=2 我等着要呢!
人气:284 ℃ 时间:2019-08-24 07:15:49
解答
3m+4n-[2m+(5m-2n)-3n]
=3m+4n-2m-5m+2n+3n
=-4m+9n
= -4*1 +9 *2
=-4+18
=14 m=1么??m=1 不是你写的嘛
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