-2x^2+76x-558=0

Solution for -2x^2+76x-558=0 equation:

-2x^2+76x-558=0

a = -2; b = 76; c = -558;
Δ = b2-4ac
Δ = 762-4·(-2)·(-558)
Δ = 1312
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{1312}=\sqrt{16*82}=\sqrt{16}*\sqrt{82}=4\sqrt{82}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(76)-4\sqrt{82}}{2*-2}=\frac{-76-4\sqrt{82}}{-4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(76)+4\sqrt{82}}{2*-2}=\frac{-76+4\sqrt{82}}{-4}
$