1/x+1/3x=1/18

Solution for 1/x+1/3x=1/18 equation:

1/x+1/3x=1/18

We move all terms to the left:

1/x+1/3x-(1/18)=0


Domain of the equation: x!=0

x∈R



Domain of the equation: 3x!=0

x!=0/3

x!=0

x∈R


We add all the numbers together, and all the variables

1/x+1/3x-(+1/18)=0

We get rid of parentheses

1/x+1/3x-1/18=0

We calculate fractions


(-9x^2)/54x^2+54x/54x^2+18x/54x^2=0

We multiply all the terms by the denominator


(-9x^2)+54x+18x=0

We add all the numbers together, and all the variables

(-9x^2)+72x=0

We get rid of parentheses

-9x^2+72x=0

a = -9; b = 72; c = 0;
Δ = b2-4ac
Δ = 722-4·(-9)·0
Δ = 5184
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{5184}=72$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(72)-72}{2*-9}=\frac{-144}{-18}
=+8
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(72)+72}{2*-9}=\frac{0}{-18}
=0
$