0.1x^2-1.8=8.2

Solution for 0.1x^2-1.8=8.2 equation:

0.1x^2-1.8=8.2

We move all terms to the left:

0.1x^2-1.8-(8.2)=0

We add all the numbers together, and all the variables

0.1x^2-10=0

a = 0.1; b = 0; c = -10;
Δ = b2-4ac
Δ = 02-4·0.1·(-10)
Δ = 4
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4}=2$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-2}{2*0.1}=\frac{-2}{0.2}
=-10
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+2}{2*0.1}=\frac{2}{0.2}
=10
$