x^2+8x-672=0

Solution for x^2+8x-672=0 equation:

x^2+8x-672=0

a = 1; b = 8; c = -672;
Δ = b2-4ac
Δ = 82-4·1·(-672)
Δ = 2752
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:

$\sqrt{\Delta}=\sqrt{2752}=\sqrt{64*43}=\sqrt{64}*\sqrt{43}=8\sqrt{43}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(8)-8\sqrt{43}}{2*1}=\frac{-8-8\sqrt{43}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8)+8\sqrt{43}}{2*1}=\frac{-8+8\sqrt{43}}{2}
$