(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):

(1/8+6/8)*1/5=7/8*1/5=7/40 (3/6+2/6)*2=5/6*2=10/6=5/3=1 2/3 (17/30-4/30)*1/13=13/30*1/13=1/30 (12/9+1/9)*4=13/9*4=52/9=5 7/9 (3/6-2/6)*3=1/6*3=1/2 (3/4-2/4)*5=1/4*5=1 1/4 (15/21+1/21)*1/2=16/21*1/2=8/21 (7/10-2/10)*1/3=5/10*1/3=5/30 (3/12-1/12)*5=2/12*5=1/6*5=5/6 (3/12+2/12)*1/10=5/12*1/10=1/24 (10/12-3/12)=7/12