1. ## Solve for x

Solve the following for x:
a) b/(x-a) = 2b/(x+a)
b) (p-q*x)/t + p = (q*x-t)/p
With b) I did this:
(p-q*x)/t - (q*x-t)/p = -p
(p(p-q*x)-t(q*x-t))/pt = -p
I don't even know if thats right. But I got stuck and couldn't go any further. I just need someone to help me through the steps. Thanks.

2. Hi there,

Originally Posted by grooverandshaker
Solve the following for x:
a) b/(x-a) = 2b/(x+a)
$\displaystyle \frac{b}{x-a} = \frac{2b}{x+a}$

Cross multiply gives,

$\displaystyle b(x+a) = 2b(x-a)$

Now expand each side, what do you get.

3. Thanks so much. I didn't even think to cross multiply.
I ended up getting x=3a. Hopefully thats right.

4. Originally Posted by grooverandshaker
Solve the following for x:
b) (p-q*x)/t + p = (q*x-t)/p
With b) I did this:
(p-q*x)/t - (q*x-t)/p = -p
(p(p-q*x)-t(q*x-t))/pt = -p
I don't even know if thats right. But I got stuck and couldn't go any further. I just need someone to help me through the steps. Thanks.
No need to get fancy with your starting point. You have a common denominator of pt, so
(p-q*x)/t + p = (q*x-t)/p

(pt)(p-qx)/t + (pt)p = (pt)(qx-t)/p

(p)(p-qx) + tp^2 = (t)(qx-t)

p^2 - pqx + tp^2 = qtx - t^2

Can you take it from here?

-Dan

5. Thanks so much. I didn't think I was on the right track.
I can take it from there.
Thanks again everyone.