72.25=2x^2

Solution for 72.25=2x^2 equation:

72.25=2x^2

We move all terms to the left:

72.25-(2x^2)=0

a = -2; b = 0; c = +72.25;
Δ = b2-4ac
Δ = 02-4·(-2)·72.25
Δ = 578
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:

$\sqrt{\Delta}=\sqrt{578}=\sqrt{289*2}=\sqrt{289}*\sqrt{2}=17\sqrt{2}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-17\sqrt{2}}{2*-2}=\frac{0-17\sqrt{2}}{-4}
=-\frac{17\sqrt{2}}{-4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+17\sqrt{2}}{2*-2}=\frac{0+17\sqrt{2}}{-4}
=\frac{17\sqrt{2}}{-4}
$