1. x/10 = 3

   x = 3 * 10

   x = 30

 2.  72/y = 8

   72 = 8y

   y = 72/8

   y = 9

  3. 64/(x+3) = 8

   64 = 8(x+3)

   64 = 8x + 24

   8x = 64 - 24

   8x = 40

   x = 40/8

   x = 5

Пошаговое объяснение:

Ответ:

1.

x/10=3

x = 10 * 3 = 30

2.

72/y=8

72 = 8y

y = 72/8 = 9

3.

64/(x+3)=8

64 = 8(x+3)

64 = 8x + 24

8x = 64 - 24

8x = 40

x = 40/8 = 5