(x+3)(x+3)=124

Solution for (x+3)(x+3)=124 equation:

(x+3)(x+3)=124

We move all terms to the left:

(x+3)(x+3)-(124)=0

We multiply parentheses ..

(+x^2+3x+3x+9)-124=0

We get rid of parentheses

x^2+3x+3x+9-124=0

We add all the numbers together, and all the variables

x^2+6x-115=0

a = 1; b = 6; c = -115;
Δ = b2-4ac
Δ = 62-4·1·(-115)
Δ = 496
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:

$\sqrt{\Delta}=\sqrt{496}=\sqrt{16*31}=\sqrt{16}*\sqrt{31}=4\sqrt{31}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(6)-4\sqrt{31}}{2*1}=\frac{-6-4\sqrt{31}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(6)+4\sqrt{31}}{2*1}=\frac{-6+4\sqrt{31}}{2}
$