5/x+2=4x

Solution for 5/x+2=4x equation:

5/x+2=4x

We move all terms to the left:

5/x+2-(4x)=0


Domain of the equation: x!=0

x∈R


We add all the numbers together, and all the variables

-4x+5/x+2=0

We multiply all the terms by the denominator


-4x*x+2*x+5=0

We add all the numbers together, and all the variables

2x-4x*x+5=0

Wy multiply elements

-4x^2+2x+5=0

a = -4; b = 2; c = +5;
Δ = b2-4ac
Δ = 22-4·(-4)·5
Δ = 84
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{84}=\sqrt{4*21}=\sqrt{4}*\sqrt{21}=2\sqrt{21}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2)-2\sqrt{21}}{2*-4}=\frac{-2-2\sqrt{21}}{-8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2)+2\sqrt{21}}{2*-4}=\frac{-2+2\sqrt{21}}{-8}
$