Find rational numbers A & B given the attached formula 

Please check the image posted. I don't think this is all that complicated, but I've not studied maths for like 10 years & I'm currently on a refresher course, I keep going around in circles with this example question and would like to see the workings as i assume I'm missing something obvious. My approach was to multiply by 1, find the value of a in terms of b, substitute that into the equation and then solve for b... 

But in my answer box I'm not allowed variables so although I get to:


That is not a valid answer because it can't contain b, but if I substitute that in place of a into the original formula and try to find b it all cancels each other out and I'm left with 0. So unless it's a trick and the answer is zero, I'm pretty lost.

Apologies for the horrendous text formula, this is just how I have to enter it on the site.


Answers can be viewed only if
  1. The questioner was satisfied and accepted the answer, or
  2. The answer was disputed, but the judge evaluated it as 100% correct.
View the answer
  • Gah that was so simple, I'd not clicked that the fraction I had was already in the format of the other side of the equation (after the multiplication by 1). Every time I'm tripping up it's the simple things! Cheers for your time.

The answer is accepted.
Join Matchmaticians Affiliate Marketing Program to earn up to 50% commission on every question your affiliated users ask or answer.