5 уравнения только не через дискриминант

$x^2 + 18 + 9x = 0 x^2 + 9x + 18 = 0 (x + 3)(x + 6) = 0 x + 3 = 0 , x + 6 = 0 x1 = -3 , x2 = -6$

$9x^2 + 16 = 24x$
$9x^2 - 24x + 16 = 0$
$x^2 - \frac{8x}{3} + \frac{16}{9} = 0$
$(x - \frac{4}{3})^2 = 0$
$x - \frac{4}{3} = 0$
$x1,2 = \frac{4}{3}$

$7x^2 = 3 - 20x 7x^2 + 20x - 3 = 0 (x + 3)(7x - 1) = 0 x + 3 = 0 , 7x - 1 = 0 x = -3 , 7x = 1$
$x1 = -3 , x2 = \frac{1}{7}$

$-6x^2 + 8x - 10 = 0$
Решений нет.

$x - 11x^2 = 0$
$-x(11x - 1) = 0 |*(-1) x(11x - 1) = 0 x = 0 ; 11x = 1$
$x1 = 0 ; x2 = \frac{1}{11}$

$x^2 - 0,04 = 0$
$x^2 - \frac{1}{25} = 0$
$\frac{1}{25} (5x - 1)(5x + 1) = 0 (5x - 1)(5x + 1) = 0 5x - 1 = 0 ; 5x + 1 = 0 5x = 1 ; 5x = -1$
$x1 = \frac{1}{5} ; x2 = - \frac{1}{5}$
$x1 = 0.2 ; x2 = -0.2$

$2n^2 = 7n + 9 2n^2 - 7n - 9 = 0 (n + 1)(2n - 9) = 0 n + 1 = 0 ; 2n - 9 = 0 n =-1 ; 2n = 9$
$n1 = -1 ; n2 = \frac{9}{2}$
$n1 = -1 ; n2 = 4.5$