1. Applications of Systems of Linear Equations
i.e. Word Problems!!!

2. Piggy Bank
A child has 25 coins in a piggy bank consisting of dimes and quarters. The total value of the coins is $3.70. Find the number of dimes and the number of quarters.

3. Piggy Bank We have two unknowns in this problem,
Let d =
Let q =
We have two totals we are concerned with,
The total number of ____________
The total amount of ____________

4. Piggy Bank How can we verbally represent the total number of coins?
How can we algebraically represent the total number of coins?

5. Piggy Bank
How can we verbally represent the total amount of money in the piggy bank?
How can we algebraically represent the total amount of money in the piggy bank?

6. Piggy Bank
We have two linear equations – what should we do??

7. The Chemist
You are in Chem. lab and in order to pass your lab you need to make 3 gallons of a solution that is 12% acid. To make the required mixture you need to mix two solutions. One solution is 8% acid and another is 18% acid. How many gallons of each acid should be mixed to produce 30 gallons of a solution that is 12% acid?

8. The Chemist We have two unknowns in this problem,
Let x =
Let y =
We have two totals we are concerned with,
The total volume of ____________

9. The Chemist
How can we verbally represent the total volume of solution?
How can we algebraically represent the total volume of solution?

10. The Chemist How can we verbally represent the total volume of acid?
How can we algebraically represent the total volume of acid?

11. The Chemist
Again we have two linear equations – what should we do???

12. The Entrepreneur
Lavely Inc. has daily fixed costs from salaries, rent, and other operations of $600. Each widget Lavely Inc makes costs $25 and sells for $45. a.) Determine the cost C of producing x widgets per day.

13. The Entrepreneur
b.) Determine the revenue R of selling x widgets per day.

14. The Entrepreneur
c.) Graph the cost and revenue functions – what does the intersection represent?