(5\7+1\21):2, (1\4-1\12)*5, (5\6-1\4):7

Question

(5\7+1\21):2, (1\4-1\12)*5, (5\6-1\4):7

Answer 1

(15/21+1/21):2=16/21*1/2=8/21
(3/12-1/12)*5=1/6*5=5/6
(10/12-3/12):7=7/12*1/7=1/12