A. No x value can have multiple different outputs.
D. The change in y between x values is 4 but the function when x is 0 is -2
First subtract the C to move it to the other side
c-P=b+4a
Then subtract the 4a as well
4a-c-p=b
Arlene; shadow 5ft: 6ft tall. = 5:6
billboard; shadow 35ft: x ft tall = 5:6.
35 * 6 / 5 = 42.
billboard is (C).42ft tall.