1/2x-9=3x+4

Solution for 1/2x-9=3x+4 equation:

1/2x-9=3x+4

We move all terms to the left:

1/2x-9-(3x+4)=0


Domain of the equation: 2x!=0

x!=0/2

x!=0

x∈R


We get rid of parentheses

1/2x-3x-4-9=0

We multiply all the terms by the denominator


-3x*2x-4*2x-9*2x+1=0

Wy multiply elements

-6x^2-8x-18x+1=0

We add all the numbers together, and all the variables

-6x^2-26x+1=0

a = -6; b = -26; c = +1;
Δ = b2-4ac
Δ = -262-4·(-6)·1
Δ = 700
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:

$\sqrt{\Delta}=\sqrt{700}=\sqrt{100*7}=\sqrt{100}*\sqrt{7}=10\sqrt{7}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-26)-10\sqrt{7}}{2*-6}=\frac{26-10\sqrt{7}}{-12}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-26)+10\sqrt{7}}{2*-6}=\frac{26+10\sqrt{7}}{-12}
$