8/5-7/8+2/5-1/8=(8/5+2/粗森5)链裂-(7/8+1/8)=2-1=1 满意岩唤亩望采纳
8/穗漏5-7/8+2/5-1/8=(8/5+2/梁芦5)-(7/猜渣烂8+1/8)=2-1=1