Frank was learning how to use pairs of points to find the slopes of lines. His homework asked him to explain how he used the pairs of points in this table to find the slope of a line. x y
12 42
16 56
Frank wrote, "The easiest way to find the slope is to divide y by x. The slope of this line would be 4212, or 72."

Show another way to find the slope of the line that passes through the points in the table. Your way must be different from Frank's way.

Write an example that shows that Frank's method will not work to find the slope of ANY line.