1/3x+7-x=18

Solution for 1/3x+7-x=18 equation:

1/3x+7-x=18

We move all terms to the left:

1/3x+7-x-(18)=0


Domain of the equation: 3x!=0

x!=0/3

x!=0

x∈R


We add all the numbers together, and all the variables

-1x+1/3x-11=0

We multiply all the terms by the denominator


-1x*3x-11*3x+1=0

Wy multiply elements

-3x^2-33x+1=0

a = -3; b = -33; c = +1;
Δ = b2-4ac
Δ = -332-4·(-3)·1
Δ = 1101
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-33)-\sqrt{1101}}{2*-3}=\frac{33-\sqrt{1101}}{-6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-33)+\sqrt{1101}}{2*-3}=\frac{33+\sqrt{1101}}{-6}
$