# Math Help - Rational expressions

1. ## Rational expressions

I did a few more of these types of problems...could someone please take a look at them...I would like to make sure that I am doing the correctly...

2. Originally Posted by aikenfan
I did a few more of these types of problems...could someone please take a look at them...I would like to make sure that I am doing the correctly...
You really need to work on using parenthesis. For example in 7 you have [tex]2x + 1(x + 1)[tex] instead of $(2x + 1)(x + 1)$. You have a similar error in 8 and 14. (This, in fact, caused your answers to 8 and 14 to be incorrect.)

In 11, $-3(x - 1)$ is equal to what?

The rest looks good.

-Dan

3. For number 8, I now get: (2x^2 + 4)/ (x-2)(x+2)
For number 14, I get (-7x^2 + 65x + 372)/(x + 4)(x - 3)

4. Originally Posted by aikenfan
For number 8, I now get: (2x^2 + 4)/ (x-2)(x+2)
$(x^2 + 4x + 4) + (x^2 - 4x + 4) =$?

Originally Posted by aikenfan
For number 14, I get (-7x^2 + 65x + 372)/(x + 4)(x - 3)
Yes, but it is not simplified. The numerator factors.
(By the way, you could've simplified the first term in the original problem.)

-Dan

5. The numerator for 8 is 2x^2 + 8

6. 93 and -28 multiply to get -2604 and add to get 65...im a little confused...what do I do with that now?
it would be (x + 93)(x - 28)?

7. Originally Posted by aikenfan
For number 8, I now get: (2x^2 + 4)/ (x-2)(x+2)
For number 14, I get (-7x^2 + 65x + 372)/(x + 4)(x - 3)
Originally Posted by aikenfan
93 and -28 multiply to get -2604 and add to get 65...im a little confused...what do I do with that now?
The hint is that there is a cancellation in your answer. So think of it this way instead: does $-7x^2 + 65x + 372$ contain a factor of either $x + 4$ or $x - 3$?

-Dan