490=(x+10)(x-11)

Solution for 490=(x+10)(x-11) equation:

490=(x+10)(x-11)

We move all terms to the left:

490-((x+10)(x-11))=0

We multiply parentheses ..

-((+x^2-11x+10x-110))+490=0


We calculate terms in parentheses: -((+x^2-11x+10x-110)), so:

(+x^2-11x+10x-110)

We get rid of parentheses

x^2-11x+10x-110

We add all the numbers together, and all the variables

x^2-1x-110

Back to the equation:

-(x^2-1x-110)


We get rid of parentheses

-x^2+1x+110+490=0

We add all the numbers together, and all the variables

-1x^2+x+600=0

a = -1; b = 1; c = +600;
Δ = b2-4ac
Δ = 12-4·(-1)·600
Δ = 2401
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2401}=49$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(1)-49}{2*-1}=\frac{-50}{-2}
=+25
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1)+49}{2*-1}=\frac{48}{-2}
=-24
$