# Thread: Transposing question

1. ## Transposing question

(New here, hope I'm posting in the right forum...)

Hello! I am working on a set of 30 problems to do with transposing equations. I have been doing well up until now, but I have hit this at question 28:

y = (a + x) / (5 - bx) rearranged for x

I know that the answer should be:

x = (5y - a) / (1 + by)

My working so far is:

y(5 - bx) = a + x

5y - ybx = a + x

...and now I get stuck. I can't seem to isolate x. I see that both the question and answer are equal but I don't see how they got there (also confused where the constant "1" came from). Any help with this would be greatly appreciated!

2. ## Re: Transposing question

Looks good so far

$\displaystyle 5y - ybx = a + x$

Now put the x's on the same side.

$\displaystyle 5y -a= x+ybx$

Factor out x.

$\displaystyle 5y -a= x(1+yb)$

Finish him off.

3. ## Re: Transposing question

Ah thank you very much. My knowledge of factoring was lacking and I didn't see I could do it there. Sorted!