2x^2-40x-168=0

Solution for 2x^2-40x-168=0 equation:

2x^2-40x-168=0

a = 2; b = -40; c = -168;
Δ = b2-4ac
Δ = -402-4·2·(-168)
Δ = 2944
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:

$\sqrt{\Delta}=\sqrt{2944}=\sqrt{64*46}=\sqrt{64}*\sqrt{46}=8\sqrt{46}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-40)-8\sqrt{46}}{2*2}=\frac{40-8\sqrt{46}}{4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-40)+8\sqrt{46}}{2*2}=\frac{40+8\sqrt{46}}{4}
$