Joe buys a set of books that cost $45.58. he gives the cashier three (3) $20 bills and three (3) pennies. how much change should joe get back?

Joe should get $14.45 back. 

This is because you must subtract the total cost from the total amount given. If we add the 3 $20 bills together, we get $60. Then is we add the 3 pennies together we get .03. If we add those two both together we get a total of $60.03.

Now we must subtract the cost given from the overall dollar given: 

60.03 - 45.58 = 14.45 

According to the question the cost of the book is $45.58

Money given by Joe is three $20 bills and three pennies.

So, total amount given by Joe to the cashier is = $60 + $0.03
= $60.03

Therefore the amount of change that Joe should get back is = Total amount given by Joe to cashier - Cost of book

= $60.03 - $45.58

= $14.45

"Joe will get $14.45 back". (Answer)