Решите 9/25-7/20,37/42-17/24, 11/24-3/16, 9/16+7/24-3/8 решите

Надо привести к общему знаменателю:
9/25-7/20=36/100-35/100=1/100

37/42-17/24=148/168-119/168=29/168

11/24-3/16=44/96-18/96=26/96=13/48

9/16+7/24-3/8=54/96+28/96-36/96=46/96=23/48