Answer: a)
b)
c)
d) 
Step-by-step explanation:
Since f is an exponential function.
So, it is expressed as

Here f is the present value
p is the initial value
r is the rate of growth per time period
t is the time period.
(a) b represents the 1-unit growth factor for f.

(b) c represents the n n-unit growth factor for f.

(c) d represents the m m-unit growth factor for f.

Write a formula that expresses c in terms of b.
Since
Hence, a)
b)
c)
d) 
First you convert 20% into a decimal which is 0.2 and multiply that by 42 and you get 8.4, that's the discount. Then you subtract 8.4 from 42 and get $33.60 which is your answer. Hope this helps!!
D. Since we know that 1 ticket = $8 we would multiply to figure out how much 7 tickets were. (7x$8). And to figure out his change you would subtract the ticket amount from $100 :) Hope this helps