Решительно уравнения а^2+4,2=49,09 И 2/7x^2-14=0

1) a² + 4,2 = 49,09
    a² = 49,09 - 4,2
    a² = 44,89
    a₁ = 6,7       a₂ = - 6,7
2) $\frac{2}{7 x^{2} }- 14= 0$
$\frac{2}{7 x^{2} }= 14$
$7 x^{2} = \frac{2}{14}$
$7 x^{2} = \frac{1}{7}$
$x^{2} = \frac{1}{7}:7= \frac{1}{7} * \frac{1}{7} = \frac{1}{49}$
$x _{1} = \sqrt{ \frac{1}{49} }= \frac{1}{7}$
$x _{2} = - \sqrt{ \frac{1}{49} } = - \frac{1}{7}$