28=4.5x^2

Solution for 28=4.5x^2 equation:

28=4.5x^2

We move all terms to the left:

28-(4.5x^2)=0

We get rid of parentheses

-4.5x^2+28=0

a = -4.5; b = 0; c = +28;
Δ = b2-4ac
Δ = 02-4·(-4.5)·28
Δ = 504
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{504}=\sqrt{36*14}=\sqrt{36}*\sqrt{14}=6\sqrt{14}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-6\sqrt{14}}{2*-4.5}=\frac{0-6\sqrt{14}}{-9}
=-\frac{6\sqrt{14}}{-9}
=-\frac{2\sqrt{14}}{-3}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+6\sqrt{14}}{2*-4.5}=\frac{0+6\sqrt{14}}{-9}
=\frac{6\sqrt{14}}{-9}
=\frac{2\sqrt{14}}{-3}
$