1. Warm Up 1)y = 3x + 2 2)y = -4x + 1 3)y = ½ x – 4 4)y = -5x + 15 Identify the slope and the y-intercept of each linear equation:

3. We have successfully identified the slope and y-intercept of a linear equation. y = mx + b y-intercept slope But why is knowing this stuff useful?

4. We can use linear equations to solve real world problems! Step 1: Find the starting value, b. Step 2: Find the value that will change, m. Step 3. Write the equation.

5. Example 1: Bob’s Car Rent A Car is offering a special. $30 for rental insurance, and then $45 dollars for each day the car is rented. Step 1: Find the starting value, b. Step 2: Find the value that will change, m. Step 3. Write the equation.

6. Awesome! You’ve got an equation. Now you can use it to solve a problem. y = 45x + 30 Bob will need the car for 5 days. How much will Bob spend?

7. Example 2: Jessica’s Birthday Jessica is having a birthday party. It costs $50 for three games of bowling. She also needs shoes for each of her friends. It costs $4 for each pair of rental shoes. Write a linear equation model this situation.

8. Great! Now use your equation to answer the question: y = 4x + 50 How much will Jessica’s birthday party cost if 12 friends can attend?

9. Example 3: Logan’s Walk Logan was doing a walk for charity, and asked for donations. Logan’s neighbor said he would make an initial donation of 5 dollars, and he would give 2 more dollars for each mile that Logan walked. Write an equation to model the situation.

10. Good job! Now use your equation to answer the question: y = 2x + 5 How much money will Logan raise if he walks 7 miles?

11. Example 4: Video Games You are buying a used Nintendo 64 for $150. Each game you purchase is $15. Write an equation to model the situation.

12. Excellent! Now use your equation to answer the question: y = 15x + 150 How much money will you spend if you buy 8 games?

13. Example 5: Blueberries Andrew planted a blueberry bush. The bush started out at 1ft in height. He took measurement every month and found that the bush was growing about a ½ inch per month. Write an equation to model the situation.

14. Excellent! Now use your equation to answer the question: y = ½x + 12 How tall will the bush be in 16 months?