3/5-1/4+3/5=? 4/15+9/20-3/10=? 18/20-(1/4+2/5)=?5/8+7/12-4/9=?17/18-(1/12+1/6)=?1/2+1/4-1/8=? (14/15-2/5)-1/3=? 4/11+2/5+7/11+1/5=?4/5-3/10+2/3=?3/7-(9/14-1/2)=? 8/9-5/9+1/6=?8...