Answer:
annual percentage yield
Step-by-step explanation:
APY means annual percentage yield
If g=guppy, go=goldfish, b=bettafish and a=angelfish we can set up expressions for each set of fish.
1g=3go
1go=2b
1b=2a
By working backwards and substituting we can finally work out 1 guppy to be equal to 12 angelfish.
Sub in what X and y are:

. Solve the exponents (if the exponent is 2 multiply the whole number by itself twice, if it were 3 you would multiply the whole number by itself three times): 3·3=9, 3·3=9: 9(9)= 81. :)
Answer:
First bank last function
Second blank, the middle function
Third blank, middle function
Fourth blank, first function