Writing Linear Equations

Writing an equation in slope-intercept form

100

The number of customers

Jarred is re-formatting computers. The cost of the program used for the re-formatting is $30. Jarred charges each customer $60 to re-format their computer. What is the input variable, x, for this situation?

200

Jarred's total income from re-formatting computers.

Jarred is re-formatting computers. The cost of the program used for the re-formatting is $30. Jarred charges each customer $60 to re-format their computer. What is the output variable, y, for this situation?

300

-30

Jarred is re-formatting computers. The cost of the program used for the re-formatting is $30. Jarred charges each customer $60 to re-format their computer. Jarred does not receive any customers in November. What is his initial value?

400

0

Jarred is re-formatting computers. The cost of the program used for the re-formatting is $30. Jarred charges each customer $60 to re-format their computer. Jarred does not receive any customers in November. How many customers did Jarred have in November?

500

y = 60x - 30

Jarred is re-formatting computers. The cost of the program used for the re-formatting is $30. Jarred charges each customer $60 to re-format their computer. What does this situation represent in slope-intercept form (hint: y=mx+b)?

Writing Linear Equations from Situations and Graphs

100

y = 30x

A dragonfly can beat its wings 30 times per second. Write an equation in slope-intercept form that shows the relationship between flying time in seconds and the number of times the dragonfly beats its wings.

200

y = 4x + 50

A balloon is released from the top of a platform that is 50 meters tall. The balloon rises at the rate of 4 meters per second. Write an equation in slope-intercept form that tells the height of the balloon above the ground after a given number of seconds.

300

y = 20x + 12

The cost of renting a sailboat at a lake is $20 per hour plus $12 for lifejackets. Write an equation in slope-intercept form that can be used to calculate the total amount you would pay for using this sailboat.

400

I will walk around and check :)

Graph y = 2x + 3

500

The slope represents how many times an item rises for each x value. The y-intercept represents the location that the graph begins prior to each x value taking place.

Explain the meaning of the slope and y-intercept (initial value) for y = 2x + 3.

Writing Linear Equations from a Table

100

y = 2.5x + 15

X 0 2 4 6 Y 15 20 25 30

200

y = 4x + 1

x 0 1 3 4 y 1 5 13 17

300

b = 3

Identify the y-intercept for the relationship. x -2 2 5 9 y 4 2 1/2 -1(1/2)

400

y = -1/2x + 3

x -2 2 5 9 y 4 2 1/2 -1(1/2)

500

Use two data points from the table to find the slope, and then locate the point on the table where x is 0 to identify the y-intercept.

Describe how you can use the information in a table showing a linear relationship to find the slope and y-intercept for the equation.

Linear Relationships

100

b = -7

Find the y-intercept. (-1, -5). y = -2x + b

200

y = -2/3x + 7

Write an equation in slope-intercept form with the slope being -2/3 and the y-intercept being 7.

300

y = 9x - 1/2

Write an equation in slope-intercept form with the slope being 9 and the y-intercept being -1/2.

400

Walking around to check your answers :)

Create a graph of the linear equation y = 5x + 1

500

y = 3x - 5

A line with a slope of 3 passes through the point (0, -5). What is the equation of this line?

Linear vs. Nonlinear

100

Linear

x 0 1 3 4 y 10 13 19 22

200

Nonlinear

x 0 1 2 6 y 5 6 9 100

300

Not linear

The height of a person and the person's age.

400

Linear

Would the graph y = 9x - 12 be linear or nonlinear?

500

Sample Answer: Graph the data points. If the points lie along a straight line, the data is linear.

How can you tell if a set of bivariate data shows a linear relationship.