Writing Linear Equation Models
	Ideas	Focus on Vertical Intercept Find the vertical intercept given two points in a linear context. Find the equation of a line given two points.
	Objective	When finished with this section, the student will be able to write the equation for a linear model given two data points of a situation.

The equation of a line can be written in various forms. We will first focus on the form y = mx + b.

Of course, you could write it in the form y = b + mx if you really want.

 

To see how the rate (slope) and the starting amount (vertical intercept) relate to the graph of a line, visit and explore this great interactivity.

Another great tutorial with self quizzes can be found here

 

 

Those tutorials are fabulous. However, there's nothing like the reality of context for deep understanding.

In the following assignments, you will practice finding the equation of lines.
Remember to think about the following:

• Which variable is dependent? Which is independent?
• What is the rate? (This is the slope.)
• What is the starting amount? (This is the amount when the independent variable equals zero.)

In this assignment you will practice writing equations from graphs and by using analysis (reasoning).
If you need digital graph paper, you can find some here.

Click here to download Assignment 7.03a

In this assignment you will practice writing equations from tables.

Click here to download Assignment 7.03b

In this assignment you will practice writing equations when you only know two points and there is no context.
Remember that in these abstract problems the numbers could mean just about anything. So if you're having difficulty, think of a situation in life that might help you grasp the problem. For example, the points (2, 5) and (6, 8) could be from a context of (# of hours, # of doughnuts eaten).

Click here to download Assignment 7.03c