4x^2=720

Solution for 4x^2=720 equation:

4x^2=720

We move all terms to the left:

4x^2-(720)=0

a = 4; b = 0; c = -720;
Δ = b2-4ac
Δ = 02-4·4·(-720)
Δ = 11520
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:

$\sqrt{\Delta}=\sqrt{11520}=\sqrt{2304*5}=\sqrt{2304}*\sqrt{5}=48\sqrt{5}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-48\sqrt{5}}{2*4}=\frac{0-48\sqrt{5}}{8}
=-\frac{48\sqrt{5}}{8}
=-6\sqrt{5}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+48\sqrt{5}}{2*4}=\frac{0+48\sqrt{5}}{8}
=\frac{48\sqrt{5}}{8}
=6\sqrt{5}
$