Answer:
Change = 20 - 3g
Step-by-step explanation:
If g is the number of guppies that Mr. Bolden bought and $3 is the price of each guppy, we can calculate the cost of all the guppies as g times $3 or:
3g
If he paid with a $20 bill, the change that he got back is the difference between 20 and 3g, so the algebraic expression for the change is:
Change = 20 - 3g