-10x(x+1=10)

Solution for -10x(x+1=10) equation:

-10x(x+1=10)

We move all terms to the left:

-10x(x+1-(10))=0

We add all the numbers together, and all the variables

-10x(x-9)=0

We multiply parentheses

-10x^2+90x=0

a = -10; b = 90; c = 0;
Δ = b2-4ac
Δ = 902-4·(-10)·0
Δ = 8100
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{8100}=90$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(90)-90}{2*-10}=\frac{-180}{-20}
=+9
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(90)+90}{2*-10}=\frac{0}{-20}
=0
$