1. Not quite. What did you do with the (2) and the (3) to get its LCM? That's what you have to do with the (2) and the (x+2) in this situation.

2. okay, would it be 2x+4?!?!?!?

3. There you go. I'd probably write it as 2(x+2) to emphasize how you got it. Now that you know what the common denominator is, can you add the fractions together?

4. YES!!!! so would the overall answer =x+9?

5. No, I don't think so. Do this problem step-by-step. After you've found the common denominator, you add the fractions. What do you get when you do that?

6. when i add them i get x-1-4 over 2x+4
than i get X-5over 2x+4
then, x-5=2x+4
then, -5=x+4
then, =x+9

7. Aha. You're missing a very important step. Let's say you're adding the fractions

$\dfrac{1}{2}+\dfrac{1}{3}.$

We've already determined that the LCM of the denominators, which is the same thing as the common denominator, is 6. What would your next step be in this addition problem?

8. 1x1=1 and 2x3=6
=1/6

9. No, no, no. You've found the common denominator. Now you have to get the common denominator. You do that by multiplying fractions by fancy ways of writing 1 in order to obtain the common denominator in each denominator. Let me illustrate:

$\displaystyle \frac{1}{2}+\frac{1}{3}=\frac{1}{2}\left(\frac{3}{ 3}\right)+\frac{1}{3}\left(\frac{2}{2}\right).$

So far, you would agree I haven't changed anything, right? I've multiplied each fraction by something that's equal to 1 (the fractions that are in parentheses). But I've chosen those numbers carefully so that when I multiply out the denominators, I'll get the common denominator that I need. Thus, the next step is to multiply out the fractions, which you can do the way you want to do it:

$\displaystyle\frac{1}{2}\left(\frac{3}{3}\right)+\ frac{1}{3}\left(\frac{2}{2}\right)=\frac{3}{6}+\fr ac{2}{6}.$

Do you see how this is done? And do you know what the next steps are?

10. yes i understand! after that would i add then and get 6/6=6?

11. I'm not so sure you understand as well as you think you do. Yes, you would add, but the steps would look more like this:

$\dfrac{3}{6}+\dfrac{2}{6}=\dfrac{3+2}{6}=\dfrac{5} {6}.$

12. oh i get it now

13. Ok. So, picking back up from where we left off at post # 21, you're trying to add the two fractions

$\dfrac{x-1}{2}-\dfrac{4}{x+2}.$

You've determined that the least common denominator is $2(x+2).$ Now you have to get the common denominator. What do you get?

14. now for my question, i have worked it out on a piece of paper and i get the answer as 2x^2 - 8x +12, would i then do quadratic equation to get the answer?

15. I think you might be skipping steps there. That's not the quadratic that I get. Post your work, please.

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