h^2+6h-691=0

Solution for h^2+6h-691=0 equation:

h^2+6h-691=0

a = 1; b = 6; c = -691;
Δ = b2-4ac
Δ = 62-4·1·(-691)
Δ = 2800
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$h_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$h_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{2800}=\sqrt{400*7}=\sqrt{400}*\sqrt{7}=20\sqrt{7}$
$h_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(6)-20\sqrt{7}}{2*1}=\frac{-6-20\sqrt{7}}{2}
$
$h_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(6)+20\sqrt{7}}{2*1}=\frac{-6+20\sqrt{7}}{2}
$