3a+1/a=8

Solution for 3a+1/a=8 equation:

3a+1/a=8

We move all terms to the left:

3a+1/a-(8)=0


Domain of the equation: a!=0

a∈R


We multiply all the terms by the denominator


3a*a-8*a+1=0

We add all the numbers together, and all the variables

-8a+3a*a+1=0

Wy multiply elements

3a^2-8a+1=0

a = 3; b = -8; c = +1;
Δ = b2-4ac
Δ = -82-4·3·1
Δ = 52
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{52}=\sqrt{4*13}=\sqrt{4}*\sqrt{13}=2\sqrt{13}$
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-8)-2\sqrt{13}}{2*3}=\frac{8-2\sqrt{13}}{6}
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-8)+2\sqrt{13}}{2*3}=\frac{8+2\sqrt{13}}{6}
$