315=3x2-17

Solution for 315=3x2-17 equation:

315=3x^2-17

We move all terms to the left:

315-(3x^2-17)=0

We get rid of parentheses

-3x^2+17+315=0

We add all the numbers together, and all the variables

-3x^2+332=0

a = -3; b = 0; c = +332;
Δ = b2-4ac
Δ = 02-4·(-3)·332
Δ = 3984
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:

$\sqrt{\Delta}=\sqrt{3984}=\sqrt{16*249}=\sqrt{16}*\sqrt{249}=4\sqrt{249}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-4\sqrt{249}}{2*-3}=\frac{0-4\sqrt{249}}{-6}
=-\frac{4\sqrt{249}}{-6}
=-\frac{2\sqrt{249}}{-3}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+4\sqrt{249}}{2*-3}=\frac{0+4\sqrt{249}}{-6}
=\frac{4\sqrt{249}}{-6}
=\frac{2\sqrt{249}}{-3}
$