m-3的绝对值+n+2的绝对值=0 求3(m-2n)-5(m-1)-2(4-5n)的值

问题描述:

m-3的绝对值+n+2的绝对值=0 求3(m-2n)-5(m-1)-2(4-5n)的值

m-3的绝对值+n+2的绝对值=0
则m=3,n=-2
3(m-2n)-5(m-1)-2(4-5n)
=3m-6n-5m+5-8+10n
=-2m+4n-3
=-6-8-3
=-17