Thread: 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.

Hi there,

Originally Posted by grooverandshaker

Solve the following for x:
a) b/(x-a) = 2b/(x+a)

Cross multiply gives,



Now expand each side, what do you get.

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

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

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