12x^2-72=3x^2+1692

Solution for 12x^2-72=3x^2+1692 equation:

12x^2-72=3x^2+1692

We move all terms to the left:

12x^2-72-(3x^2+1692)=0

We get rid of parentheses

12x^2-3x^2-1692-72=0

We add all the numbers together, and all the variables

9x^2-1764=0

a = 9; b = 0; c = -1764;
Δ = b2-4ac
Δ = 02-4·9·(-1764)
Δ = 63504
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{63504}=252$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-252}{2*9}=\frac{-252}{18}
=-14
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+252}{2*9}=\frac{252}{18}
=14
$