3㎡-(2㎡一m+1)+2(-3+m-㎡),其中m=-7

问题描述:

3㎡-(2㎡一m+1)+2(-3+m-㎡),其中m=-7

3㎡-(2㎡一m+1)+2(-3+m-㎡)
=3㎡-2㎡+m-1-6+2m-2㎡
=-㎡+3m-7
=-(-7)^2+3(-7)-7
=-49-21-7
=-77


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