如果2m-3n=2 m+2m=1,那么3m-n+3=?

问题描述:

如果2m-3n=2 m+2m=1,那么3m-n+3=?

2m-3n=2 m+2n=1 两式相加:3m-n=3 所以3m-n+3=3+3=6