This set of ordered pairs is a function (22, 4), (21, 1), (0, 0), (1, 1), and (2, 4).

Please explain like you were teaching how you can know this is a function.

Step-by-step explanation:

You know these ordered pairs are considered a function, because the x intercepts do not repeat themselves. In other words, each input numbers are different. If these ordered pairs were not a function, the x intercept would be repeating. For example,  22 is already a x intercept, (22,4), if 22 was put in as another x intercept like,(22,1) these ordered pairs would not be a function.

i believe it is c.y = 9x

rise over run. 9 units up over 1 unit right or 9/1

3

step-by-step explanation:

divide 13.5 by 9 to get the scale factor. it equals 1.5

2 * 1.5 = 3