
Mike C. answered 06/30/13
Enthusiastic Tutor for Middle and High School Students
Elaborating on what Ralph said, first you must determine the slope of AB. Using the rise-run formula, the slope is (15-(-2))/(-3-14) = 17/17 = 1.
The point-slope form of a line is y = mx + b, where m is the slope and b is the y-intercept. Our line connecting A and B, having a slope of 1, should be y = x + b. Because we're looking for a parallel line that goes through C (which is (10, 10)), that parallel line should also have a slope of 1, so it's also in the form of y = x + c, where c is a different constant than that of the line connecting AB.
Now let's plug the values of x and y in:
10 = 10 + c;
c = 0.
Hence, the line we have is y = x.