(12x+15)(12x-15)=0

Solution for (12x+15)(12x-15)=0 equation:

(12x+15)(12x-15)=0

We use the square of the difference formula

144x^2-225=0

a = 144; b = 0; c = -225;
Δ = b2-4ac
Δ = 02-4·144·(-225)
Δ = 129600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{129600}=360$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-360}{2*144}=\frac{-360}{288}
=-1+1/4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+360}{2*144}=\frac{360}{288}
=1+1/4
$