7+1/2x=3/4x+9

Solution for 7+1/2x=3/4x+9 equation:

7+1/2x=3/4x+9

We move all terms to the left:

7+1/2x-(3/4x+9)=0


Domain of the equation: 2x!=0

x!=0/2

x!=0

x∈R



Domain of the equation: 4x+9)!=0

x∈R


We get rid of parentheses

1/2x-3/4x-9+7=0

We calculate fractions


4x/8x^2+(-6x)/8x^2-9+7=0

We add all the numbers together, and all the variables

4x/8x^2+(-6x)/8x^2-2=0

We multiply all the terms by the denominator


4x+(-6x)-2*8x^2=0

Wy multiply elements

-16x^2+4x+(-6x)=0

We get rid of parentheses

-16x^2+4x-6x=0

We add all the numbers together, and all the variables

-16x^2-2x=0

a = -16; b = -2; c = 0;
Δ = b2-4ac
Δ = -22-4·(-16)·0
Δ = 4
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4}=2$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-2)-2}{2*-16}=\frac{0}{-32}
=0
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2)+2}{2*-16}=\frac{4}{-32}
=-1/8
$