0=9x^2-144

Solution for 0=9x^2-144 equation:

0=9x^2-144

We move all terms to the left:

0-(9x^2-144)=0

We add all the numbers together, and all the variables

-(9x^2-144)=0

We get rid of parentheses

-9x^2+144=0

a = -9; b = 0; c = +144;
Δ = b2-4ac
Δ = 02-4·(-9)·144
Δ = 5184
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{5184}=72$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-72}{2*-9}=\frac{-72}{-18}
=+4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+72}{2*-9}=\frac{72}{-18}
=-4
$