798=(2x+2)(x-1)

Solution for 798=(2x+2)(x-1) equation:

798=(2x+2)(x-1)

We move all terms to the left:

798-((2x+2)(x-1))=0

We multiply parentheses ..

-((+2x^2-2x+2x-2))+798=0


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

(+2x^2-2x+2x-2)

We get rid of parentheses

2x^2-2x+2x-2

We add all the numbers together, and all the variables

2x^2-2

Back to the equation:

-(2x^2-2)


We get rid of parentheses

-2x^2+2+798=0

We add all the numbers together, and all the variables

-2x^2+800=0

a = -2; b = 0; c = +800;
Δ = b2-4ac
Δ = 02-4·(-2)·800
Δ = 6400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{6400}=80$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-80}{2*-2}=\frac{-80}{-4}
=+20
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+80}{2*-2}=\frac{80}{-4}
=-20
$