Multiplying equations - spiral coil heat transfer

1. Aug 1, 2011

luznyr

"multiplying equations" - spiral coil heat transfer

Hi, I was wondering if anyone could explain to me what is meant in this article by "Multiplying equations 8 & 9". I have both equation 8 and equation 9 however I cannot seem to work out how to get equation 10...not sure if it's something simple I'm missing, thanks in advance.

2. Aug 1, 2011

pmsrw3

Re: "multiplying equations" - spiral coil heat transfer

That means $\mbox{LHS of (8)} \times \mbox{LHS of (9)} = \mbox{RHS of (8)} \times \mbox{RHS of (9)}$. (Although I don't quite understand how they get from there to (10).)

3. Aug 1, 2011

luznyr

Re: "multiplying equations" - spiral coil heat transfer

Ok cheers, I did try that but I couldn't get it. Will have to try again, thanks :)

4. Aug 2, 2011

luznyr

Re: "multiplying equations" - spiral coil heat transfer

Thanks for your help, didn't end up needing to multiply them just required a lot of tedious manipulation!