86=0.14*x(^)2

Solution for 86=0.14*x(^)2 equation:

86=0.14x(^)2

We move all terms to the left:

86-(0.14x(^)2)=0

We get rid of parentheses

-0.14x^2+86=0

a = -0.14; b = 0; c = +86;
Δ = b2-4ac
Δ = 02-4·(-0.14)·86
Δ = 48.16
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{48.16}}{2*-0.14}=\frac{0-\sqrt{48.16}}{-0.28}
=-\frac{\sqrt{}}{-0.28}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{48.16}}{2*-0.14}=\frac{0+\sqrt{48.16}}{-0.28}
=\frac{\sqrt{}}{-0.28}
$