7(2/5)x + 15 = -5.214/5x + 15 = -5.214/5x = -5.2 - 1514/5x = -20.2x = -20.2 * 5 / 14x = -101 / 14
Ответ: x = -101 / 14
7(2/5)x + 15 = -5.2
14/5x + 15 = -5.2
14/5x = -5.2 - 15
14/5x = -20.2
x = -20.2 * 5 / 14
x = -101 / 14
Ответ: x = -101 / 14