Ok, make sure you put the powers correctly. I know what you mean but someone else may not. So it's step 2. This is because the 4 doesn't mean add a digit.
The domain of the equation are all the possible values of the independent variables that would make the equation reasonable, possible or true. In this item, the independent variable is r. This could take a value of 0 up to the point when m is equal to zero.
m = 30 - 3r = 0
r = 10
The domain is therefore [0, 10].
The range is the value of the dependent variable which would be from 0 to the point when no video game is played. This is, [0, 30].
The function is discrete because r and m cannot take every value in the number line.
If i had to estimate i would say letter D
As the width gets larger so does the total area
