Question

помогите решить уравнение​

Answer 1

Ответ:

x= -9

$x {2} + x = 45 - 3x \\ x {2} + x - 45 + 3x = 0 \\ x {2} + 4x - 45 = 0 \\ x{2} + 9x - 5x - 45 = 0 \\ x(x + 9) - 5(x + 9) = 0 \\ (x + 9) \times (x - 5) = 0 \\ x + 9 = 0 \\ x - 5 = 0 \\ x = - 9$