She has 65 water bottles....and she is buying boxes of water bottles (x) that hold 16 water bottles each. She can only buy up to 5 water bottles.
f(x) = 16x + 65...where f(x) = total water bottles and x = number of boxes x < = 5.....here is ur restriction
the range is ur f(x) values which represent the total number of water bottles...keep in mind, she can only buy 5. Therefore, the numbers that can be subbing in for x are 0 thru 5.
So when subbing in 0 thru 5 for x, the results for f(x) are : { 65,81,97,113,129 } <== ur range
