s^2-13s=-12

Solution for s^2-13s=-12 equation:

s^2-13s=-12

We move all terms to the left:

s^2-13s-(-12)=0

We add all the numbers together, and all the variables

s^2-13s+12=0

a = 1; b = -13; c = +12;
Δ = b2-4ac
Δ = -132-4·1·12
Δ = 121
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$s_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$s_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{121}=11$
$s_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-13)-11}{2*1}=\frac{2}{2}
=1
$
$s_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-13)+11}{2*1}=\frac{24}{2}
=12
$