-2x^2-13x+7=0

Solution for -2x^2-13x+7=0 equation:

-2x^2-13x+7=0

a = -2; b = -13; c = +7;
Δ = b2-4ac
Δ = -132-4·(-2)·7
Δ = 225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{225}=15$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-13)-15}{2*-2}=\frac{-2}{-4}
=1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-13)+15}{2*-2}=\frac{28}{-4}
=-7
$