4x + 3(x + 20) = 9(x - 104x + 3x + 60 = 9x - 97x + 60 = 9x - 960 + 90 = 9x - 7150 = 2x = 150/x = 75
Ответ: x = 75.
4x + 3(x + 20) = 9(x - 10
4x + 3x + 60 = 9x - 9
7x + 60 = 9x - 9
60 + 90 = 9x - 7
150 = 2
x = 150/
x = 75
Ответ: x = 75.