Answer:
I think this is the correct answer
C=8h+12
the 8h represents the $8 per hour for renting the boat, and h represents however many hours you rent the boat for. The +12 is the initial $12 fee. This is in slope intercept form, just using different variables than y=mx+b
20...just draw 20 coins or something
X = -3, y = 2 rise over run