Решите уравнения как можно быстрее.

x = 0" alt="24 {x}^{2} = 0 = > x = 0" align="absmiddle" class="latex-formula">
$16 {x}^{2} + 9 = 0 \\ 16 {x}^{2} = - 9$
корней нет.
$81 {x}^{2} - 144x = 0 \\ 9x(x - 16) = 0 \\ x = 0 \\ x = \frac{16}{9} \\$
$4 {x}^{2} - 52x + 169 = 0 \\ {(2x - 13)}^{2} = 0 \\ 2x - 13 = 0 \\ 2x = 13 \\ x = 13 \div 2 \\$

" alt="21 {x}^{2} + 14x + 7 = 0 \\d = 196 - 588 < 0 = > " align="absmiddle" class="latex-formula">
корней нет.
$3 {(x + 2)}^{2} - 63 = 13x - 30 + {x}^{2} \\ 3( {x}^{2} + 4x + 4) - 63 - 13x + 30 - {x}^{2} = 0 \\ 3 {x}^{2} + 12x + 12 - 63 - 13x + 30 - {x}^{2} = 0 \\ 2 {x}^{2} - x - 21 = 0 \\ x = \frac{1 \pm \sqrt{1 + 168} }{4} \\ x = \frac{1 \pm13}{4} \\ x = - 3 \\ x = \frac{7}{2}$