(x+7)(x-7)=125

Solution for (x+7)(x-7)=125 equation:

(x+7)(x-7)=125

We move all terms to the left:

(x+7)(x-7)-(125)=0

We use the square of the difference formula

x^2-49-125=0

We add all the numbers together, and all the variables

x^2-174=0

a = 1; b = 0; c = -174;
Δ = b2-4ac
Δ = 02-4·1·(-174)
Δ = 696
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:

$\sqrt{\Delta}=\sqrt{696}=\sqrt{4*174}=\sqrt{4}*\sqrt{174}=2\sqrt{174}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-2\sqrt{174}}{2*1}=\frac{0-2\sqrt{174}}{2}
=-\frac{2\sqrt{174}}{2}
=-\sqrt{174}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+2\sqrt{174}}{2*1}=\frac{0+2\sqrt{174}}{2}
=\frac{2\sqrt{174}}{2}
=\sqrt{174}
$