The experienced worker works at twice the speed of the apprentice so let's call his part of any given job 2x and call the Apprentice's part of the job x.   When the work together they are ADDING there efforts so, if a job takes 3 hours than, it can be expressed as:    ...

Sorry but this does not make much sense. There are two equals signs in your denominators. I know that it is very difficult to input math information with this editor, but  please check your symbols, and submit with question again.  Thank you.

I think Vivian has done an excellent job here, and I agree with her assessment of problem 3. The way it is written, it is unsolvable with out more information. However, maybe there was a typo, and it should read: "He plans to read 20 PAGES tomorrow on his crumpet break."  If this...

To make it dead simple, a rational expression is just a fraction with some variables shoved in there, either on top or on the bottom, but usually both. It really is that simple to understand what they are, but working with rational expressions can be quite complicated.

For #1:   To be precise, this is not a polynomial. Polynomial have monomials added together arranged in descending degrees for their variables. This is called a rational expression. What you should do to simplify it, is to just cancel the powers of similar variables on the top and bottom...