SOLUTION: Hi I need a little help with this problem. The directions are to find the LCD and do not combine fractions. 13/x^2-16, 7/x-4 If you could show how you did the problem it would be

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Hi I need a little help with this problem. The directions are to find the LCD and do not combine fractions. 13/x^2-16, 7/x-4 If you could show how you did the problem it would be      Log On


   

Question 9293: Hi I need a little help with this problem. The directions are to find the LCD and do not combine fractions.
13/x^2-16, 7/x-4
If you could show how you did the problem it would be a big help.. Thank you.
Answer by rapaljer(4671) About Me  (Show Source):
You can put this solution on YOUR website!
13%2F%28x%5E2-16%29 and +7%2F%28x-4%29+

Notice that the denominator of the first fraction factors so you really have:
13%2F%28%28x-4%29%28x%2B4%29%29 and +7%2F%28x-4%29+

The objective is to get the denominators to be the same. You are allowed to multiply the numerator and denominator of any given fraction by the same quantity. Can you see that the Least Common Denominator (LCD) is (x-4)(x+4)?

The first denominator HAS the LCD, but the second denominator is missing a factor. The second denominator is missing a factor of (x+4). So you must multiply the numerator and denominator of the second fraction by (x+4):

13%2F%28%28x-4%29%28x%2B4%29%29 and +%287%28x%2B4%29%29%2F%28%28x-4%29%28x%2B4%29%29+ or
13%2F%28%28x-4%29%28x%2B4%29%29 and +%287x%2B28%29%2F%28%28x-4%29%28x%2B4%29%29+

R^2 at SCC