1. Day 83 – Business Project

2. Word Problem
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 $ on her purchase of 8 items.

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

4. 1. Using the information from the previous slide, complete the following table: 2. Circle the row that has a total cost of $60.50.
Number of Smarties Bags
Number of Dum-Dum lollipops Bags
Total Cost for 8 Items ($) 8
$68.00 1 7
$66.50 2 6
$65.00 3 5
$63.50 4
$62.00
$60.50
$59.00
$57.50
$56.00

5. 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. 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. 6. Write a system of equations to model the situation. Items: Cost:

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

10. 7. How many bags of Smarties did Mrs. Smith buy
7. How many bags of Smarties did Mrs. Smith buy? 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 to eliminate y) (nothing needs to change here)

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

12. 8. How many bags of Dum-Dum lollipops did Mrs. Smith buy
8. How many bags of Dum-Dum lollipops did Mrs. Smith buy? 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 to eliminate x) (nothing needs to change here)

13. Solve 1 2

14. Answer Key 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. Solve 1 2

16. Answer Key 2(2x + 3y) = 2(─1) 3(5x ─ 2y) = 3(─12)
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.