Question

Решить уравнение:
4(9 + 7х ) + 21;
4(9 + 7х ) + 21 = 393;

Answer 1

1) 4(9+7x) + 21 = 393

36 + 28x + 21 = 393

28x + 57 = 393

28x = 393 - 57

28n = 336

n = 336/28

n = 12

Answer 2

Ответ:

1)393-21=4(9+7x)

2)372:4=(9+7x)

3)93-9=7x

4)84:7

x=12