4.3.3 – Writing a system

1. 4.3.3 – Writing a system

2. We can extend the idea of a system now back into some simple applications • One skill we will need is the ability to write our own system of inequalities based on information we are presented

3. Key Words • Certain key words will arise often, and will help you write the inequalities • Keywords: at least, no more, larger, smaller, maximum, minimum, fewer than, more than

4. Using the inequalities, you could possibly graph them for solutions, or determine test points yourself based on the inequalities

5. Example. You are making a new deck for your backyard. You need at least 20 pieces of large cut wood, and at least 40 pieces of smaller cut wood. Your car can only fit 80 pieces of wood, regardless of size. Write a system of inequalities to show how much wood can be carried.

6. Example. You are at the store buying different types of soda in 2 liter bottles. You need at least 10 bottles of coke, and 8 bottles of Dr Pepper. Each bottle of Coke costs $5, while each Dr Pepper costs $4.25. You can only spend up to $100. Write a system of inequalities for the number of bottles we can purchase.

7. Example. Javi goes to a Miami Heat game. While there, he decides he wants to purchase souvenirs. He wants to buy at least 2 shirts, and 5 pairs of socks. Each shirt costs $22.00, while each pair of socks costs $9.00. He can only spend up to $110.00. Write a system of inequalities for the number of shirts and socks he may purchase.

8. Assignment • Pg. 190 • 51, 53, 54, 56, 57, 59