Answer:
A)

B)

C)

Step-by-step explanation:
We are given the function:

A)
Given that h(1) = 20, we want to find <em>k</em>.
h(1) = 20 means that <em>h</em>(x) = 20 when <em>x</em> = 1. Substitute:

Simplify:

Anything raised to zero (except for zero) is one. Therefore:

B)
Given that h(1) = 40, we want to find 2<em>k</em> + 1.
Likewise, this means that <em>h</em>(x) = 40 when <em>x</em> = 1. Substitute:

Simplify:

We can take the natural log of both sides:

By definition, ln(e) = 1. Hence:

Therefore:

C)
Given that h(1) = 10, we want to find <em>k</em> - 3.
Again, this meas that <em>h</em>(x) = 10 when <em>x</em> = 1. Substitute:

Simplfy:

Take the natural log of both sides:

Therefore:

Therefore:

Rebecca payed $35 for the video game, simple math.
The error is that he probably forgot the decimal point thus causing him to say '"hundred" instead of "and" for the decimal point.
<span>The price usually goes up. If lots of people want something, you have to pay more to get it.</span>