Answer: if 0 < x ≤ 450, y = $60.
if 450 < x ; y = $60 + (x - 450min)*$0.35
Step-by-step explanation:
Here x will represent the number of minutes.
with $60 you have 450 minutes, and you must pay 60 regardless of how much minutes you use.
so if 0 < x ≤ 450, y = $60.
now, if you call for more than 450 minutes, you get an additional of $0.35 per minute, then we have:
if 450 < x ; y = $60 + (x - 450min)*$0.35
where we use (x - 450)*$0.35 because any minute after the 450 minute mark is considerated an additional time.
So our piecewise function is:
if 0 < x ≤ 450, y = $60.
if 450 < x ; y = $60 + (x - 450min)*$0.35
