x2=18.75

Solution for x2=18.75 equation:

x2=18.75

We move all terms to the left:

x2-(18.75)=0

We add all the numbers together, and all the variables

x^2-18.75=0

a = 1; b = 0; c = -18.75;
Δ = b2-4ac
Δ = 02-4·1·(-18.75)
Δ = 75
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:

$\sqrt{\Delta}=\sqrt{75}=\sqrt{25*3}=\sqrt{25}*\sqrt{3}=5\sqrt{3}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-5\sqrt{3}}{2*1}=\frac{0-5\sqrt{3}}{2}
=-\frac{5\sqrt{3}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+5\sqrt{3}}{2*1}=\frac{0+5\sqrt{3}}{2}
=\frac{5\sqrt{3}}{2}
$