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? b + 23 = 17; b = 6 23b = 17; b = 6 6b = 17; b = 23 b + 6 = 17; b = 11