rearranging an equation to make a particular variable the subject.

xy=1

t^2x-y=t^3-1/t

I have tried putting x=1/y into the bottom equation but it gets messy. Is there another way of doing this. I do not want the solution, just a helpful pointer. Thanks in advance.

What is the actual question?

Express x and y in terms of the other variable.
I have edited the original post in case of confusion.

Where does this come from? Is this the whole question?

It is the entire question. The question comes from a CD-ROM extension exercise for OCR C1. It is an old spec(2004). I am studying for pleasure rather than towards an exam. I have been asked this a few times on this site. Is it permitted to ask questions unless you are studying towards a goal? If so I apologise. I just love maths and am keen to understand.

It's fine to study for fun but this question is not C1 level and seems very strange to me. I wonder if there is an error - what are the answers supposed to be?

(x=t,y=1/t), (x=-1/t^3,y=-t^3). I have had this response from other members of this forum, to different questions from the same book. As I mentioned it is not required C1 learning. The CD is designed to test the more able pupils. you may ask why then am I attempting these questions!! I just love to learn.

OL - I substitute y = 1/x then multiplied through by x and t.

I got a quadratic that I could factorise.

Thanks a lot. I actually did this before but I was thinking of a quadratic in t! After finding a quadratic in x and using the formula, the algebra was still a bit hard but I got there. Once again thanks a lot. I am quite new to this site so I do not know how to rep you. It goes without saying that I would if I knew.