A = 4/7 + 3/14 = 8/14 + 3/14 = 11/14
B = 5/3 + 7/8 = 40/24 + 21/24 = 61/24
C = ( 2 - 12/5 ) + 21/15 - 7/4 = 10/5 - 12/5 + 84/60 - 105/60
= 120/60 - 144/60 + 84/60 - 105/60
= 204/60 - 39/60 = 165/60 = 33/12 = 11/4
D = - 200/120 + 4/3 = - 200/120 + 160/120 = - 40/120 = - 1/3
E = 12/15 * 25/9 = 300/135 = 150/31
F = 3/7 : 33/49 = 3/7 * 49/33 = 147/231 = 7/11
G = 2/5 - 7/4 * 3 - ( 4 + 7/6 ) = 2/5 - 21/4 - 24/6 + 7/6
= 2/5 - 21/4 - 17/6
= 24/60 - 315/60 - 170/60
= - 461/60