Question

PLEASE HELP PLEASE PLEASE

Answer 1

9514 1404 393

Answer:

  f(x) = {0, x≤ 1; 4(x -1), 1 < x ≤ 6; 2.5x +5, x > 6}

Step-by-step explanation:

The hourly rate gives you the slope of the function in the relevant interval. The added constant is chosen to make the function continuous.

That is, at 1 hour, the charge is zero, so the next segment (4x+b) must have a value of b that makes the charge for 1 hour be zero. That will be b=-4.

Likewise, for more than 6 hours, the charge will be (2.5x+b), where b is chosen to make this expression match the charge for 6 hours. We know the charge for 6 hours is 4(6) -4 = 20, so b must match ...

  2.5(6) +b = 20

  b = 20 -15 = 5

The segment from 1 to 6 hours is f(x) = 4x -4.

The segment for more than 6 hours is f(x) = 2.5x +5.

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Alternate solution

Since the charge is zero for the first hour, the first segment could be considered to be charging only for hours after the first. That is, an alternate expression for hours 1–6 could be 4(x -1). Likewise, we could say the expression for hours more than 6 is 2.5(x +2).

Answer 2

Answer:

The top-left box should be 4x, and the bottom-left box should be 2.50x.

Step-by-step explanation:

Because the cost from 2 hours to 6 hours is 4 dollars per hour, it is 4x.

Likewise, because the cost over 6 hours is 2.50 dollars per hour, the cost is 2.50x.

Everything else seems fine.

Hope this helps!