m-{3n-4m+[m-5(m-n)+m]}=_.

问题描述:

m-{3n-4m+[m-5(m-n)+m]}=______.

原式=m-{3n-4m+[m-5m+5n+m]}=m-{3n-4m+5n-3m}=m-3n+4m-5n+3m=8m-8n.
故答案为:8m-8n.