(1/8+3/4):5 , (1/2+1/3)*2 , (17/30-2/15):13 , (4/3+1/9)*4 , (1/2-1/3)*3 , (3/4-1/2)*5 , (5/7+1/21):2 , (7/10-1/5):3 , (1/4-1/12)*5 , (1/4+1/6):10 ,
(5/6-1/4):