Explanation:
For the question question, since they are giving you the function you just need to find the input that matches the expected output (y) which will be the number of miles biked. So what numbers multiplied by 12 give you 12, 36, and 48?
You could substitute y into an algebraic function to find these values.
We'll use 36 miles as an example.
If 12x = y then
12x = 36
divide both sides by 12
x = 3
For the second question you are given the x value (number of guests) and just need to calculate y (cupcakes each guest is allowed) by dividing 30 by the number of guests (x).