# Math Help - Proportions

1. ## Proportions

I just wanted to make sure I got this problem correctly http://img109.imageshack.us/img109/7831/91757261.png
I got x = 5 did I do this one correctly?

Also I need help on a problem that looks like this http://img109.imageshack.us/img109/7831/91757261.png

I don't know how to set up a proportion for that one, so can anyone help me with this? Thanks.

2. Originally Posted by Jubbly
I just wanted to make sure I got this problem correctly http://img109.imageshack.us/img109/7831/91757261.png
I got x = 5 did I do this one correctly?

Also I need help on a problem that looks like this http://img109.imageshack.us/img109/7831/91757261.png

I don't know how to set up a proportion for that one, so can anyone help me with this? Thanks.
looks like your two links are the same one.....
here is the proportion:

$\frac{x}{x+5} = \frac{2x-8}{x+8}$ (= 1:1)

x(x + 8) = (2x - 8)(x + 5)
$x^2 + 8x = 2x^2 + 10x - 8x - 40$
$x^2 - 6 - 40 = 0$
(x - 10)(x + 4) = 0
x = 10 or x = -4