Решите уравнение 1) (12m - 5m) * 4=252 2) 45 : (4m - m) = 3 3) (16m + 5m) : 18=7

1. 7·m·4 = 252,

28·m = 252,

m = 252:28,

m = 9.

Проверка:

(12·9 - 5·9) ·4 = 252,

(108 - 45) ·4 = 252,

63·4 = 252,

252 = 252.

2. 45:3·m = 3,

3·m = 45:3,

3·m = 15,

m = 15:3,

m = 5.

Проверка:

45: (4·5 - 5) = 3,

45:15 = 3,

3 = 3.

3. 21·m:18 = 7,

21·m = 7·18,

21·m = 126,

m = 126:21,

m = 6.

Проверка:

(16·6 + 5·6) : 18 = 7,

(96 + 30) : 18 = 7,

126:18 = 7,

7 = 7.