You have a gift certificate to a book store worth $95. Each paperback book is $10 and each hardcover book is $17. You must spend at least $20 in order to use the gift certificate. Write and graph a system of inequalities to model the number of each kind of books you can buy. Let x= the number of paperback books and y= the number of hardback books
Accepted Solution
A:
You make a system of inequality to spend at least $20. The word "at least" means you can spend equal to $20 or higher than $20. Or you can write it as, ⇒ what you buy should be ≥ 20
Input the price to the inequality above ⇒ what you buy should be ≥ 20 ⇒ paperback price + hardcover price ≥ 20 ⇒ 10x + 17y ≥ 20
Because the number of paperback books and the number of hardcover books can't be negative, make new inequality forms ⇒ x ≥ 0 ⇒ y ≥ 0