X-12=1/3x

Solution for X-12=1/3x equation:

X-12=1/3X

We move all terms to the left:

X-12-(1/3X)=0


Domain of the equation: 3X)!=0

X!=0/1

X!=0

X∈R


We add all the numbers together, and all the variables

X-(+1/3X)-12=0

We get rid of parentheses

X-1/3X-12=0

We multiply all the terms by the denominator


X*3X-12*3X-1=0

Wy multiply elements

3X^2-36X-1=0

a = 3; b = -36; c = -1;
Δ = b2-4ac
Δ = -362-4·3·(-1)
Δ = 1308
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:

$\sqrt{\Delta}=\sqrt{1308}=\sqrt{4*327}=\sqrt{4}*\sqrt{327}=2\sqrt{327}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-36)-2\sqrt{327}}{2*3}=\frac{36-2\sqrt{327}}{6}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-36)+2\sqrt{327}}{2*3}=\frac{36+2\sqrt{327}}{6}
$