For this case the first thing you should know is that by definition the slope of the line is given by: m = (y2-y1) / (x2-x1) Where we have two ordered pairs: P1 = (x1, y1) P2 = (x2, y2) We observe then that according to the formula, the error of mine was to invert the numerator with the denominator. Answer: C: Mia switched the numerator and the denominator.
