3 3/10 ÷ (1/4 × X + 5/12) - 2 3/5 = 7/10

Відповідь:

X = 2 1/3

Покрокове пояснення:

3 3/10 ÷ (1/4 × X + 5/12) - 2 3/5 = 7/10

3 3/10 ÷ (1/4 × X + 5/12) = 7/10 + 2 6/10

3 3/10 ÷ (1/4 × X + 5/12) = 3  3/10

1/4X + 5/12 = 3 3/10 ÷ 3 3/10

1/4X + 5/12 = 1

1/4X = 12/12 - 5/12

1/4X = 7/12

X = 7/12 : 1/4

X = 2 1/3