№157. Решите уравнение: 1) x + 2,65 = 7; 2) 34,68 - x = 2,68; 3) x - 10,365 = 11,635; 4) 20,73 + x = 30.

Решение:

1. $$ x + 2,65 = 7 $$

   $$ x = 7 - 2,65 $$

   $$ x = 4,35 $$

2. $$ 34,68 - x = 2,68 $$

   $$ x = 34,68 - 2,68 $$

   $$ x = 32 $$

3. $$ x - 10,365 = 11,635 $$

   $$ x = 11,635 + 10,365 $$

   $$ x = 22 $$

4. $$ 20,73 + x = 30 $$

   $$ x = 30 - 20,73 $$

   $$ x = 9,27 $$

Ответ: 1) 4,35; 2) 32; 3) 22; 4) 9,27.