m-{3n-4m+[m-5(m-n)+m]}=_.
问题描述:
m-{3n-4m+[m-5(m-n)+m]}=______.
答
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.