15x^2=120

Solution for 15x^2=120 equation:

15x^2=120

We move all terms to the left:

15x^2-(120)=0

a = 15; b = 0; c = -120;
Δ = b2-4ac
Δ = 02-4·15·(-120)
Δ = 7200
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:

$\sqrt{\Delta}=\sqrt{7200}=\sqrt{3600*2}=\sqrt{3600}*\sqrt{2}=60\sqrt{2}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-60\sqrt{2}}{2*15}=\frac{0-60\sqrt{2}}{30}
=-\frac{60\sqrt{2}}{30}
=-2\sqrt{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+60\sqrt{2}}{2*15}=\frac{0+60\sqrt{2}}{30}
=\frac{60\sqrt{2}}{30}
=2\sqrt{2}
$