1. simple equation

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

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

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

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

Multiply both sides by (d-2)

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

$\displaystyle d+8 = \frac94\d-2)$

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

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

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

$\displaystyle 32 + 18 = 5d$

$\displaystyle 5d = 50$

$\displaystyle d = 10$

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

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

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

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