能简算的简算:17/18-2/5-2/5=
问题描述:
能简算的简算:17/18-2/5-2/5=
答
17/18-2/5-2/5
= 17/18-(2/5+2/5)
= 17/18-4/5
= 85/90-72/90
= 13/90