(s-2)(s+6)=153

Solution for (s-2)(s+6)=153 equation:

(s-2)(s+6)=153

We move all terms to the left:

(s-2)(s+6)-(153)=0

We multiply parentheses ..

(+s^2+6s-2s-12)-153=0

We get rid of parentheses

s^2+6s-2s-12-153=0

We add all the numbers together, and all the variables

s^2+4s-165=0

a = 1; b = 4; c = -165;
Δ = b2-4ac
Δ = 42-4·1·(-165)
Δ = 676
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$s_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$s_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{676}=26$
$s_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(4)-26}{2*1}=\frac{-30}{2}
=-15
$
$s_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(4)+26}{2*1}=\frac{22}{2}
=11
$