Really simple problem - rearranging equations, getting it upside down.
Hey I know this is really simple and silly, I used to find this really easy, I've been confused by a book and now feel rather stupid at not being able to even rearrange equations.. I get it right, right, right and then suddenly I get one written exactly upside down when compared to the book's answer.
Here's an upside down one:
to make the subject
Their answer was
I've spent a few hours rereading my chapters and getting a bit upset...what have I done wrong? (Doh)