Answer:
Number of books did Gillian buy is 11.
Step-by-step explanation:
Given : Gillian purchased 25 books at the library book sale. Each hardcover book cost $1.50, and each paperback book cost $0.50. Gillian spent a total of $26.50.
To find : How many paperback books did Gillian buy?
Solution :
The book costs can be represented by the system of equations below.
[tex]h+p= 25[/tex] ......(1)
[tex]1.50 h + 0.50 p = 26.50[/tex] ......(2)
Solving the system of equations by substitution method
Substitute h=25-p from (1) into (2)
[tex]1.50(25-p) + 0.50 p = 26.50[/tex]
[tex]37.5-1.50p + 0.50 p = 26.50[/tex]
[tex]p = 11[/tex]
Substitute back in equation (1),
[tex]h+11= 25[/tex]
[tex]h=14[/tex]
i.e. there are 11 paperback books and 14 hardcover books.
Therefore, Number of books did Gillian buy is 11.
