869. Решите уравнение: 1) 15,62 + x = 20; 2) 9,54 - x = 7,268; 3) x - 36,76 = 19,24; 4) x + 0,24 = 8,1.

Решение:

1. \[ 15,62 + x = 20 \]
2. \[ x = 20 - 15,62 \]
3. \[ x = 4,38 \]
4. \[ 9,54 - x = 7,268 \]
5. \[ x = 9,54 - 7,268 \]
6. \[ x = 2,272 \]
7. \[ x - 36,76 = 19,24 \]
8. \[ x = 19,24 + 36,76 \]
9. \[ x = 56 \]
10. \[ x + 0,24 = 8,1 \]
11. \[ x = 8,1 - 0,24 \]
12. \[ x = 7,86 \]

Ответ: 4,38; 2,272; 56; 7,86.