Question is in the picture ⬇

B.3^-4

Here is this step we need to subtract the power having base same and when four comes up the sign changes into + because -X- is +.

3^-8+4=3^-4

(2,20) means that the 2 is 2 hours and 20 is 20$. so there both 20$ for 2 hours only the same price. like it says. so, the dunk tank and the bounce house are the same price (20$) for the same amount of time (2 hours).

hope i