125=5x2

Solution for 125=5x2 equation:

125=5x^2

We move all terms to the left:

125-(5x^2)=0

a = -5; b = 0; c = +125;
Δ = b2-4ac
Δ = 02-4·(-5)·125
Δ = 2500
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2500}=50$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-50}{2*-5}=\frac{-50}{-10}
=+5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+50}{2*-5}=\frac{50}{-10}
=-5
$