# Thread: simple equation

1. ## simple equation

$d+8/d-2=9/4$

Thankful for help. Now I don't get how to write this. d+8 should be the numerator, d-2 the denominator. How do i get that?

2. Hi

$\frac{d+8}{d-2} = \frac94$

First note that $d \neq 2$ because the denominator must not be equal to 0

Multiply both sides by (d-2)

$\frac{d+8}{d-2} \d-2) = \frac94\d-2)" alt="\frac{d+8}{d-2} \d-2) = \frac94\d-2)" />

$d+8 = \frac94\d-2)" alt="d+8 = \frac94\d-2)" />

Multiply both sides by 4
$4(d+8) = 9(d-2)$

Spoiler:
Expand both sides
$4d+32 = 9d-18$

$32 = 9d-18-4d = 5d-18$

$32 + 18 = 5d$

$5d = 50$

$d = 10$

3. Originally Posted by strunz
$d+8/d-2=9/4$

Thankful for help. Now I don't get how to write this. d+8 should be the numerator, d-2 the denominator. How do i get that?
There is a latex tutorial somewhere. You can type this problem as I have done below and click on someone's text to see what they typed.

\frac{d+8}{d-2} = \frac{9}{4}

Multiply both sides by (d-2) to give

$d+8 = \frac{9d}{4} - \frac{9}{2}$

$\frac{9d-4d}{4} = -\frac{9-16}{2}$

Then multiply by 4/5 to get your answer