26=(2x-6)(x+3)

Solution for 26=(2x-6)(x+3) equation:

26=(2x-6)(x+3)

We move all terms to the left:

26-((2x-6)(x+3))=0

We multiply parentheses ..

-((+2x^2+6x-6x-18))+26=0


We calculate terms in parentheses: -((+2x^2+6x-6x-18)), so:

(+2x^2+6x-6x-18)

We get rid of parentheses

2x^2+6x-6x-18

We add all the numbers together, and all the variables

2x^2-18

Back to the equation:

-(2x^2-18)


We get rid of parentheses

-2x^2+18+26=0

We add all the numbers together, and all the variables

-2x^2+44=0

a = -2; b = 0; c = +44;
Δ = b2-4ac
Δ = 02-4·(-2)·44
Δ = 352
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:

$\sqrt{\Delta}=\sqrt{352}=\sqrt{16*22}=\sqrt{16}*\sqrt{22}=4\sqrt{22}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-4\sqrt{22}}{2*-2}=\frac{0-4\sqrt{22}}{-4}
=-\frac{4\sqrt{22}}{-4}
=-\frac{\sqrt{22}}{-1}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+4\sqrt{22}}{2*-2}=\frac{0+4\sqrt{22}}{-4}
=\frac{4\sqrt{22}}{-4}
=\frac{\sqrt{22}}{-1}
$