Реши уравнения 39: (x•4-25) = 13, 40-720: (y+34) = 32.

1) 39 : (x * 4 - 25) = 13;

x * 4 - 25 = 39 : 13;

x * 4 - 25 = 3;

x * 4 = 3 + 25;

x * 4 = 28;

х = 28 : 4;

х = 7.

Проверка:

39 : (7 * 4 - 25) = 13;

39 : (28 - 25) = 13;

39 : 3 = 13;

13 = 13.

2) 40 - 720 : (y + 34) = 32;

720 : (y + 34) = 40 - 32;

720 : (y + 34) = 8;

y + 34 = 720 : 8;

y + 34 = 90;

у = 90 - 34;

у = 56.

Проверка:

40 - 720 : (56 + 34) = 32;

40 - 720 : 90 = 32;

40 - 8 = 32;

32 = 32.