Решите уравнение: -3x^2+7x+45 = (x+6)^2

$- 3 {x}^{2} + 7x + 45 = {(x + 6)}^{2} \\ - 3 {x}^{2} + 7x + 45 = {x}^{2} + 12x + 36 \\ - 3{x}^{2} - {x}^{2} + 7x - 12x = 36 - 45 \\ - 4 {x}^{2} - 5x = - 9 \\ 4 {x}^{2} + 5x = 9 \\ 4 {x}^{2} + 5x - 9 = 0 \\ x = \frac{ - 5 + - \sqrt{ {5}^{2} - 4 \times 4 \times ( - 9) } }{2 \times 4} \\ x = \frac{ - 5 + - \sqrt{169} }{8} \\ x = \frac{ - 5 + - 13}{8}$
x1 = -9/4
x2 = 1

x1 =-2.25