x+(20/100)x=90

Solution for x+(20/100)x=90 equation:

x+(20/100)x=90

We move all terms to the left:

x+(20/100)x-(90)=0


Domain of the equation: 100)x!=0

x!=0/1

x!=0

x∈R


We add all the numbers together, and all the variables

x+(+20/100)x-90=0

We multiply parentheses

20x^2+x-90=0

a = 20; b = 1; c = -90;
Δ = b2-4ac
Δ = 12-4·20·(-90)
Δ = 7201
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(1)-\sqrt{7201}}{2*20}=\frac{-1-\sqrt{7201}}{40}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1)+\sqrt{7201}}{2*20}=\frac{-1+\sqrt{7201}}{40}
$