# Thread: Help needed to simplify a formula - this is probably easy!!!

1. ## Help needed to simplify a formula - this is probably easy!!!

Hi,

Can this formula be simplified?

x = (d/(a-b)) - (d/a)

Any help would be much appreciated...

Thanks,
Chris

2. ## Re: Help needed to simplify a formula - this is probably easy!!!

Originally Posted by cjcass
Can this formula be simplified?

x = (d/(a-b)) - (d/a)
Yes, get a common denominator and subtract the two fractions.

3. ## Re: Help needed to simplify a formula - this is probably easy!!!

Hi,
I'm not a mathematician so could you please give me the result.
Many thanks in anticipation,
Chris

4. ## Re: Help needed to simplify a formula - this is probably easy!!!

Sorry, hope I didn't come across rude in my last reply!!

5. ## Re: Help needed to simplify a formula - this is probably easy!!!

Originally Posted by cjcass
I'm not a mathematician so could you please give me the result.
Well, I'm not going to do your work for you. If you really have no idea what to do, you might want to try to find a tutorial online. I found this on Google, it covers addition and subtraction of rational expressions towards the bottom.

For your problem, note that our lowest common denominator is $a(a - b).$ We need to get this denominator in both fractions. To do that, we should multiply the numerator and denominator of the first fraction by $a,$ and we multiply the numerator and denominator of the second fraction by $(a-b).$

6. ## Re: Help needed to simplify a formula - this is probably easy!!!

Ok, now I'm with you - many thanks for your help!!