Not sure if your the same person but I had already done the work for this problem....
(c)
We notice that they already have common denominators, therefore we can just add the numerators up.
(x+y+x-y)/2xy=
2x/2xy
Dividing both top and bottom by 2x, we get
<h2><u><em>
1/y</em></u></h2>
-Hunter
I will solve for you right now.
If you are reffering to this dot plot, it would be 13 trees being studied.
Is there a picture or is that it