-12x(-13x)=256

Solution for -12x(-13x)=256 equation:

-12x(-13x)=256

We move all terms to the left:

-12x(-13x)-(256)=0

We multiply parentheses

156x^2-256=0

a = 156; b = 0; c = -256;
Δ = b2-4ac
Δ = 02-4·156·(-256)
Δ = 159744
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:

$\sqrt{\Delta}=\sqrt{159744}=\sqrt{4096*39}=\sqrt{4096}*\sqrt{39}=64\sqrt{39}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-64\sqrt{39}}{2*156}=\frac{0-64\sqrt{39}}{312}
=-\frac{64\sqrt{39}}{312}
=-\frac{8\sqrt{39}}{39}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+64\sqrt{39}}{2*156}=\frac{0+64\sqrt{39}}{312}
=\frac{64\sqrt{39}}{312}
=\frac{8\sqrt{39}}{39}
$