Linear Equations Applications

1. Linear Equations Applications

2. Ex #1: The base pay of a water-delivery person is $210 per week. He also earns 20% commission on any sale he makes. • Write an equation that relates his total earnings to his sales. • What is his total earnings if he sold $200 of water? • How much did he sell if his total earnings was $240?

3. Ex #2: A dog kennel charges a base rate of $15 and $5 per day. • Write an equation for the total cost of putting a dog in the kennel for ddays. • How much would it cost to have your dog in the kennel for 12 days? • How many days did a customer leave their dog at the kennel if the total cost was $$50?

4. Ex# 3: The freshman class holds a car wash to raise money. A local merchant donates all of the supplies. A wash costs $5 per car and $6.50 per SUV. The class made $800 on the car wash. • Write an equation that relates the number of cars washed and the number of SUVs washed. • How many SUVs were washed if 95 cars were washed? • How many cars were washed if 100 SUVs were washed?

5. Ex #4: A tire dealer sells Supreme tires for $24 each and Prestige tires for $56 each. During one week, the sales for both tires totaled $2688. • Write an equation that relates the number of Supreme tires sold and the number of Prestige tires sold. • How many Prestige tires were sold if 35 Supreme tires were sold? • How many Supreme tires were sold if 18 Prestige tires were sold?

6. Summary • Define your variables (let statements) • Write a linear model / equation • Solve the problem • Answer the question with words!

7. Summary (cont.) • Slope Intercept Form of a Line: y = mx + b • Use when a rate and a “starting point” are given • Can be expressed as a function • Standard Form of a Line: Ax + By = C • Use when two independent rates are given • This form is not in function form