2x^2-40x+39=0

Solution for 2x^2-40x+39=0 equation:

2x^2-40x+39=0

a = 2; b = -40; c = +39;
Δ = b2-4ac
Δ = -402-4·2·39
Δ = 1288
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:

$\sqrt{\Delta}=\sqrt{1288}=\sqrt{4*322}=\sqrt{4}*\sqrt{322}=2\sqrt{322}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-40)-2\sqrt{322}}{2*2}=\frac{40-2\sqrt{322}}{4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-40)+2\sqrt{322}}{2*2}=\frac{40+2\sqrt{322}}{4}
$