Please help 20 points.
 Marco went to the library. He checked out 6 movies. The rest of the items he checked out were books. He checked out a total of 17 items. How many books did he check out?
 Use the variable b to represent the number of books Marco checked out.
 Which equation represents this situation and its solution?
 6b = 17; b = 23
 b + 6 = 17; b = 11
 b + 23 = 17; b = 6
 23b = 17; b = 6