Question

в корне7х-1=2
$\sqrt{7x - 1} = 2$
Помогите решить

Answer 1

$\sqrt{7x - 1} = 2 \\ 7x - 1 = 4 \\ 7x = 4 + 1 \\ 7x = 5 \div 7 \\ x = \frac{5}{7} \\ \\ \sqrt{7 \frac{5}{7} - 1 } = 2 \\ \\ 2 = 2 \\ \\ x = \frac{5}{7}$