18^2+0.2x^2=0.8x^2

Solution for 18^2+0.2x^2=0.8x^2 equation:

18^2+0.2x^2=0.8x^2

We move all terms to the left:

18^2+0.2x^2-(0.8x^2)=0

We add all the numbers together, and all the variables

0.2x^2-(0.8x^2)+324=0

We get rid of parentheses

0.2x^2-0.8x^2+324=0

We add all the numbers together, and all the variables

-0.6x^2+324=0

a = -0.6; b = 0; c = +324;
Δ = b2-4ac
Δ = 02-4·(-0.6)·324
Δ = 777.6
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{777.6}}{2*-0.6}=\frac{0-\sqrt{777.6}}{-1.2}
=-\frac{\sqrt{}}{-1.2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{777.6}}{2*-0.6}=\frac{0+\sqrt{777.6}}{-1.2}
=\frac{\sqrt{}}{-1.2}
$