Brett cannot spend more than $30, so the cost of the books and the shipping charge have to be less or equal to $30, we can express this as in an inequality, like this:
[tex]4n+2\leq30[/tex]Where n is the number of books purchased, since each book costs $4, 4 times n equals the total cost of the books and 2 is the shipping charge. We can solve for n in the inequality like this:
[tex]\begin{gathered} 4n+2\leq30 \\ 4n+2-2\leq30-2 \\ 4n\leq28 \\ \frac{4n}{4}\leq\frac{28}{4} \\ n\leq7 \end{gathered}[/tex]Then, brett can afford no more than 7 books.
