X^2+40x-79=0

Solution for X^2+40x-79=0 equation:

X^2+40X-79=0

a = 1; b = 40; c = -79;
Δ = b2-4ac
Δ = 402-4·1·(-79)
Δ = 1916
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:

$\sqrt{\Delta}=\sqrt{1916}=\sqrt{4*479}=\sqrt{4}*\sqrt{479}=2\sqrt{479}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(40)-2\sqrt{479}}{2*1}=\frac{-40-2\sqrt{479}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(40)+2\sqrt{479}}{2*1}=\frac{-40+2\sqrt{479}}{2}
$