Find the lowest common denominator of the following fractions. 5/n-2 and n+2/n^2-4

The denominator of the second fraction is the difference of squares, so can be factored using the formula for that.
  (n^2 -4) = (n -2)(n +2)

Now, you will note that the second fraction has a numerator that is equal to one of the factors in the denominator. In other words, the whole fraction can be simplified to ...
  (n +2)/((n +2)(n -2)) = 1/(n -2) . . . . with the restriction n≠-2

This reduced form of the fraction has the same denominator as the first fraction, so you can say that the lowest common denominator is that: (n -2).


If there is some reason you don't want to reduce the second fraction, the lowest common denominator will be (n -2)(n +2).

In all honesty, there really is no “work” per say to show. mainly it’s just using the process of elimination. the question is asking which domain(s) would be the most appropriate for the function c(n). n is the number of observed vehicles so right away, 1, 2, and 3 can be eliminated.why? 1, 2 start in the negatives and therefore it is impossible to observe negative cars. so, #4 would be the best answer to the given problem.