Question

Решите уравнения
$7 {x}^{2} - 28 = 0$
$5x {}^{2} - x = 0$

Answer 1

$1)7x {}^{2} - 28 = 0 \\ {x}^{2} - 4 = 0 \\ {x}^{2} = 4 \\ x = ±2 \\ 2)5x {}^{2} - x = 0 \\ x(5x - 1) = 0 \\ x_{1} = 0 \\ 5x - 1 = 0 \\ 5x = 1 \\ x_{2} = \frac{1}{5}$