## sophiashaikh 2 years ago Can someone help me on a relations and functions question .....I'll post the question

1. sophiashaikh

Alright, here's how to solve B. For the first week (7 days) it's 20 dollars per day so it's \$20 x 7 = ? Then the last three days it's 17 dollars (since the price goes down) so it's \$17 * 3 = ? Multiply those two and then add up the products and that'll be the answer for b

3. sophiashaikh

I got 191

Here's how to solve c. For the first time she parked at the garage, she had the car there for five days so it's \$20 x 5 = ? For the second time she parked there, she was there for more than 7 days so first it's \$20 x 7 = ? And the last day she was there was \$17 so whatever your answer is for \$20 x 7 you add 17 dollars to and that'll be your answer.

Let me check

\$191 is correct (I really hope I'm doing this right :b ) is this k12?

7. sophiashaikh

yes it is lol

8. sophiashaikh

I got 257 for C now what? lol

That's what I got too..I'm guessing that's right :b

10. sophiashaikh

so the differnce would be \$57?

11. jim_thompson5910

for part a) it costs \$20 a day for the first week so if f(x) is the cost function, then f(x) = 20x if 0 <= x <= 7 (this is the initial charge per day) OR f(x) = 17x if x > 7 (because the cost decreases to \$17 a day after 7 days)

12. jim_thompson5910

where x = number of days parked

13. sophiashaikh

Okay that makes sense thank you

14. jim_thompson5910

yw