s^2-16s-15=0

Solution for s^2-16s-15=0 equation:

s^2-16s-15=0

a = 1; b = -16; c = -15;
Δ = b2-4ac
Δ = -162-4·1·(-15)
Δ = 316
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$s_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$s_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{316}=\sqrt{4*79}=\sqrt{4}*\sqrt{79}=2\sqrt{79}$
$s_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-16)-2\sqrt{79}}{2*1}=\frac{16-2\sqrt{79}}{2}
$
$s_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-16)+2\sqrt{79}}{2*1}=\frac{16+2\sqrt{79}}{2}
$