How is the process for simplifying 2x(x+1)/4(x+1) similar? Different?
How is the process for simplifying and multiplying fractions similar to simplifying or multiplying rational expressions?
The process for simplifying rational expressions really is the same as the process as simplifying fractions.
For example, if you were going to simplify the fraction 5/20, you would find a common divisor and divide that piece out of both the numerator and the denominator. In this example, 5 would be a common divisor.
5/20 = 1(5) / 4(5) = 1/4
In the example you listed above, there is a term that shows up in both the numerator and the denominator. To simplify the expression, you need to divide that out of both pieces. I also see an even integer in both the numerator and denominator, so you know right away that they have a common divisor that can be taken out.