Question

3 3/8 ÷ (1/14х + 5/7) = 2,1

Answer 1

3 3/8 ÷ (1/14х + 5/7) = 2,1

1/14х + 5/7 = 3 3/8 :  2,1

1/14х + 5/7 = 1 17/28

1/14х =  1 17/28 - 5/7

1/14х = 25/28

х = 25/28 : 1/14

х =12 1/2

Ответ: 12 целых одна вторая.