Chapter 6: Linear Equations & Their Graphs

6.3Applying Linear Equations

Review

• Slope:

• Point-Slope Form:

• Slope-Intercept Form:

• Standard Form:

Example 1A car dealership has 40 cars in stock. The auto manufacturer will deliver new cars to the dealership by car carrier. Each carrier holds 6 cars. Write a linear function that relates the number of carriers used to the total number of cars at the dealership. Graph the function that models the situation.

Example 1aA sporting goods store sells cans of tennis balls. There are 3 tennis balls in each can. The coach of the tennis team is buying supplies. Write a linear function that relates the number of cans to the total number of tennis balls. Graph the function that models the situation.

Example 2Students in a 9th grade class drew the following graph to represent how much money would be in the class fund after washing cars at a fundraiser.

•What does the slope and y-intercept of the graph mean for the given situation?•If the graph had the same slope but a y-intercept of 15, what could you conclude about the fundraiser?•If the graph had a slope of 5, what could you conclude about the fundraiser?

Example 2a• Suppose you drew the following graph to represent

how far you ride your bike at a steady rate. What is your rate?

• If the graph had a slope of 10, what could you conclude about your bike ride?

Example 3• A lumber yard sells pre-cut 6-, 8-, 10-, and 12-foot

beams for $1.20 per foot. Model the situation with a linear function and a graph.

Example 4• Suppose your family buys a “movie card” from a

DVD store that entitles you to rent 25 movies. You rent 3 movies per week. Write an equation and draw a graph that models the situation.

Homework

• P. 325

• 2-14 even