One reading list had a total of 12 fiction and nonfiction books. compared to the first list, there are twice as many fiction books and 3 times as many nonfiction books making a total of 28 books on the second reading list. write a system of linear equations and find the number of fiction and nonfiction books on the first list.

First we define the variables:
 x = fiction books
 y = nonfiction books
 We write the system of equations that best suits the problem.
 We have then:
 x + y = 12
 2x + 3y = 28
 Solving the system:
 x = 8
 y = 4
  
 x + y = 12 
 2x + 3y = 28
 the number of fiction and nonfiction books on the first list are: 
 8 fiction books 
 4 nonfiction books