12,5+x(2)=20

Solution for 12,5+x(2)=20 equation:

12.5+x(2)=20

We move all terms to the left:

12.5+x(2)-(20)=0

We add all the numbers together, and all the variables

x^2-7.5=0

a = 1; b = 0; c = -7.5;
Δ = b2-4ac
Δ = 02-4·1·(-7.5)
Δ = 30
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-\sqrt{30}}{2*1}=\frac{0-\sqrt{30}}{2}
=-\frac{\sqrt{}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{30}}{2*1}=\frac{0+\sqrt{30}}{2}
=\frac{\sqrt{}}{2}
$