-2x^2+52x+240=0

Solution for -2x^2+52x+240=0 equation:

-2x^2+52x+240=0

a = -2; b = 52; c = +240;
Δ = b2-4ac
Δ = 522-4·(-2)·240
Δ = 4624
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4624}=68$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(52)-68}{2*-2}=\frac{-120}{-4}
=+30
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(52)+68}{2*-2}=\frac{16}{-4}
=-4
$