x+x*(10/100)=11

Solution for x+x*(10/100)=11 equation:

x+x(10/100)=11

We move all terms to the left:

x+x(10/100)-(11)=0

We add all the numbers together, and all the variables

x+x(+10/100)-11=0

We multiply parentheses

10x^2+x-11=0

a = 10; b = 1; c = -11;
Δ = b2-4ac
Δ = 12-4·10·(-11)
Δ = 441
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{441}=21$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(1)-21}{2*10}=\frac{-22}{20}
=-1+1/10
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1)+21}{2*10}=\frac{20}{20}
=1
$