Question

5х в квадрате + 8х - 4 =0

Answer 1

$D= b^{2} -4ac=64+80=144$
$x_{1,2} = frac{-b +- sqrt{D} }{2a}$
$x_{1} = frac{-8+12}{2} = frac{2}{5}$
$x_{2} = frac{-8-12}{2} =-2$