Question

Решите уравнение: (x+3)(x-3) - x(x+4) =0

Answer 1

$(x + 3)(x - 3) - x(x + 4) = 0 \\ {x}^{2} - 9 - {x}^{2} - 4 \times x = 0 \\ - 4x = 9 \\ x = - 2 \times \frac{1}{4} \\ x = - 2.25$