38.2*7.5+75+0.75*518=750怎么巧算?
问题描述:
38.2*7.5+75+0.75*518=750怎么巧算?
答
=382*0.75+100*0.75+0.75*518
=(382+100+518)*0.75=1000*0.75=750
答
=38.2*7.5 + 7.5*10 + 7.5*51.8
=7.5*(38.2+10+51.8)
=7.5*100
=750