0=2x2+12x-1040=2(x+6x-520)=2(X-20)(x+26)

Solution for 0=2x2+12x-1040=2(x+6x-520)=2(X-20)(x+26) equation:

0=2x^2+12x-1040=2(x+6x-520)=2(x-20)(x+26)

We move all terms to the left:

0-(2x^2+12x-1040)=0

We add all the numbers together, and all the variables

-(2x^2+12x-1040)=0

We get rid of parentheses

-2x^2-12x+1040=0

a = -2; b = -12; c = +1040;
Δ = b2-4ac
Δ = -122-4·(-2)·1040
Δ = 8464
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{8464}=92$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-12)-92}{2*-2}=\frac{-80}{-4}
=+20
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-12)+92}{2*-2}=\frac{104}{-4}
=-26
$