1. D AY 83 – B USINESS P ROJECT

2. W ORD P ROBLEM Mrs. Smith decided to purchase candy for her whole class as a treat. She bought Smarties and Dum-Dum lollipops as “brain food” for their next exam. Each bag of Smarties cost $7.00 (including tax). The bag of Dum-Dum lollipops cost $8.50 (including tax). She ended up spending $60.50 on her purchase of 8 items.

3. Number of Smarties Bags Number of Dum- Dum lollipops Bags Total Cost for 8 Items ($) 0 1 2 3 4 5 6 7 8 1. Using the information from the previous slide, complete the following table: 2. Circle the row that has a total cost of $60.50.

4. Number of Smarties Bags Number of Dum- Dum lollipops Bags Total Cost for 8 Items ($) 08 $68.00 17 $66.50 26 $65.00 35 $63.50 44 $62.00 53 $60.50 62 $59.00 71 $57.50 80 $56.00 1. Using the information from the previous slide, complete the following table: 2. Circle the row that has a total cost of $60.50.

5. 3.How many bags of Smarties did Mrs. Smith buy? 4. How many bags of Dum-Dum lollipops did Mrs. Smith buy? 5. Define your variables.

6. 3.How many bags of Smarties did Mrs. Smith buy? 5 4. How many bags of Dum-Dum lollipops did Mrs. Smith buy? 3 5. Define your variables. x = number of Smarties bags y = number of Dum-Dum lollipop bags

7. 6. Write a system of equations to model the situation.

8. Items: Cost:

9. 7. How many bags of Smarties did Mrs. Smith buy?

10. Finding the number of Smarties bags means I should eliminate y since that is the variable that defines Dum-Dum lollipop bags. (multiply this equation by -8.50 to eliminate y) (nothing needs to change here)

11. 8. How many bags of Dum-Dum lollipops did Mrs. Smith buy?

12. Finding the number of Dum-Dum lollipop bags means I should eliminate x since that is the variable that defines Smarties bags. (multiply this equation by -7.00 to eliminate x) (nothing needs to change here)

13. S OLVE 2 1

14. A NSWER K EY Multiply each side of Equation 1 by ─1. Now the coefficients of these y terms are additive inverses, Substitute x = ─ 5 in Equation 1 or in Equation 2. The check is left for you.

15. S OLVE 2 1

16. A NSWER K EY Multiply each side of Equation 1 by 2 and multiply each side of Equation 2 by 3. Then the y terms will be additive inverses of each other 2(2x + 3y) = 2(─1) 3(5x ─ 2y) = 3(─12) Substitute x = ─ 2 in Equation 1 The check is left for you.