简算:(3/10-1/5+1/4)*20

问题描述:

简算:(3/10-1/5+1/4)*20

(3/10-1/5+1/4)*20
=3/10x20-1/5x20+1/4x20
=6-4+5
=7
如果本题有什么不明白可以追问,