(2/3-1/5)+(2/3-12/17)-(1/5+5/17)用简便方法计算

问题描述:

(2/3-1/5)+(2/3-12/17)-(1/5+5/17)用简便方法计算

=(2/3+2/3)-(1/5+1/5)-(12/17+5/17)
=4/3-2/5-1
=-1/15