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

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

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

We move all terms to the left:

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


Domain of the equation: 2n!=0

n!=0/2

n!=0

n∈R



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

n∈R


We get rid of parentheses

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

We calculate fractions


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

We add all the numbers together, and all the variables

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

We multiply all the terms by the denominator


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

Wy multiply elements

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

We get rid of parentheses

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

We add all the numbers together, and all the variables

-16n^2-2n=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:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

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