### Home > AC > Chapter 12 > Lesson 12.4.4 > Problem 12-106

12-106.

Write and solve an equation to answer the question below. Homework Help ✎

Lorena and Lena both work in the library. Lorena has already returned 38 books to the shelves and can shelve 16 books an hour on average. Lena, on the other hand, has already returned 52 books to the shelves and can shelve 20 books per hour on average. If together they started with a total of 252 books to return on the shelves, how much longer should it take them?

Write equations to represent the situations.

38 + 16*x* = # of books Lorena shelves

52 + 20*x* = # of books Lena shelves

252 = (38 + 16*x*) + (52 + 20*x*)

Solve for *x*.

4.5 hours