300=4x^2

Solution for 300=4x^2 equation:

300=4x^2

We move all terms to the left:

300-(4x^2)=0

a = -4; b = 0; c = +300;
Δ = b2-4ac
Δ = 02-4·(-4)·300
Δ = 4800
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:

$\sqrt{\Delta}=\sqrt{4800}=\sqrt{1600*3}=\sqrt{1600}*\sqrt{3}=40\sqrt{3}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-40\sqrt{3}}{2*-4}=\frac{0-40\sqrt{3}}{-8}
=-\frac{40\sqrt{3}}{-8}
=-\frac{5\sqrt{3}}{-1}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+40\sqrt{3}}{2*-4}=\frac{0+40\sqrt{3}}{-8}
=\frac{40\sqrt{3}}{-8}
=\frac{5\sqrt{3}}{-1}
$