x2+3.2=20

Solution for x2+3.2=20 equation:

x2+3.2=20

We move all terms to the left:

x2+3.2-(20)=0

We add all the numbers together, and all the variables

x^2-16.8=0

a = 1; b = 0; c = -16.8;
Δ = b2-4ac
Δ = 02-4·1·(-16.8)
Δ = 67.2
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{67.2}}{2*1}=\frac{0-\sqrt{67.2}}{2}
=-\frac{\sqrt{}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{67.2}}{2*1}=\frac{0+\sqrt{67.2}}{2}
=\frac{\sqrt{}}{2}
$