2/3x+4=x+9

Solution for 2/3x+4=x+9 equation:

2/3x+4=x+9

We move all terms to the left:

2/3x+4-(x+9)=0


Domain of the equation: 3x!=0

x!=0/3

x!=0

x∈R


We get rid of parentheses

2/3x-x-9+4=0

We multiply all the terms by the denominator


-x*3x-9*3x+4*3x+2=0

Wy multiply elements

-3x^2-27x+12x+2=0

We add all the numbers together, and all the variables

-3x^2-15x+2=0

a = -3; b = -15; c = +2;
Δ = b2-4ac
Δ = -152-4·(-3)·2
Δ = 249
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{-(-15)-\sqrt{249}}{2*-3}=\frac{15-\sqrt{249}}{-6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-15)+\sqrt{249}}{2*-3}=\frac{15+\sqrt{249}}{-6}
$