M取何值时,2(3M-4)的值比5(M-7)的值大8?

问题描述:

M取何值时,2(3M-4)的值比5(M-7)的值大8?
要每一步的步骤,先去括号在计算,

2(3M-4)-5(M-7)=8
6M-8-5M+35=8
M=8+8-35
M=-19