3(5x^2-6)=0

Solution for 3(5x^2-6)=0 equation:

3(5x^2-6)=0

We multiply parentheses

15x^2-18=0

a = 15; b = 0; c = -18;
Δ = b2-4ac
Δ = 02-4·15·(-18)
Δ = 1080
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:

$\sqrt{\Delta}=\sqrt{1080}=\sqrt{36*30}=\sqrt{36}*\sqrt{30}=6\sqrt{30}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-6\sqrt{30}}{2*15}=\frac{0-6\sqrt{30}}{30}
=-\frac{6\sqrt{30}}{30}
=-\frac{\sqrt{30}}{5}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+6\sqrt{30}}{2*15}=\frac{0+6\sqrt{30}}{30}
=\frac{6\sqrt{30}}{30}
=\frac{\sqrt{30}}{5}
$