x^2=12.5

Solution for x^2=12.5 equation:

x^2=12.5

We move all terms to the left:

x^2-(12.5)=0

We add all the numbers together, and all the variables

x^2-12.5=0

a = 1; b = 0; c = -12.5;
Δ = b2-4ac
Δ = 02-4·1·(-12.5)
Δ = 50
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:

$\sqrt{\Delta}=\sqrt{50}=\sqrt{25*2}=\sqrt{25}*\sqrt{2}=5\sqrt{2}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-5\sqrt{2}}{2*1}=\frac{0-5\sqrt{2}}{2}
=-\frac{5\sqrt{2}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+5\sqrt{2}}{2*1}=\frac{0+5\sqrt{2}}{2}
=\frac{5\sqrt{2}}{2}
$