2x=x+20/x+1

Solution for 2x=x+20/x+1 equation:

2x=x+20/x+1

We move all terms to the left:

2x-(x+20/x+1)=0


Domain of the equation: x+1)!=0

x∈R


We get rid of parentheses

2x-x-20/x-1=0

We multiply all the terms by the denominator


2x*x-x*x-1*x-20=0

We add all the numbers together, and all the variables

-1x+2x*x-x*x-20=0

Wy multiply elements

2x^2-1x^2-1x-20=0

We add all the numbers together, and all the variables

x^2-1x-20=0

a = 1; b = -1; c = -20;
Δ = b2-4ac
Δ = -12-4·1·(-20)
Δ = 81
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{81}=9$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-9}{2*1}=\frac{-8}{2}
=-4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+9}{2*1}=\frac{10}{2}
=5
$