We have been provided a diagram which tells us that Patti drew vertical line segments from two points to the line in her scatter plot. The first point she selected was dwarf crocodile. The second point she selected was for an Indian Gharial crocodile.
We can see that dwarf crocodile's bite force is closer to line of best fit than Indian Gharial crocodile. Indian Gharial crocodile seems to be an outlier for our data set.
Therefore, Patti's line have resulted in a predicted bite force that was closer to actual bite force for the dwarf crocodile.
15 divide 30 by 2 and you have your answer
Answer is A
The binomial can be factored using the difference of squares formula a2-b2 = (a+b) (a-b) where a=x and b=9
(X+9) x(x-9)