__Objectives__:

- I can write a linear equation from a given graph.
- I can write a linear equation from a given table of values.
- I can write a linear equation from two given points.

__What is a linear equation?__

A linear equation has two variables that when graphed it creates a straight line. Earlier you learned about

slope-intercept form. We can write linear equations in slope-intercept form so that it is easier for us to graph the equation.

Recall: We call it slope-intercept form because it is organized as that we can easily locate the slope and

y-intercept of the line. For example, the general equation for slope-intercept form is:

In this form, we can easily spot the slope, m, and the y-intercept, b.

__SLOPE__: You have learned previously that the slope is the steepness of a line. You have heard the phrase "rise over run" many times now, also known as the change in y over the change in x.__Y-INTERCEPT__: The y-intercept is the value of "y" when the line intercepts the y-axis.__Writing Linear Equations from a Graph__

In order to write the linear equation of a graph, we need to know two things: (1) Where does the line cross the

y-axis, and (2) what is the slope of the line. We will use these two pieces of information and plug them into the slope-intercept form equation. This will create a linear equation. Let's look at the steps to follow and an example:

y-axis, and (2) what is the slope of the line. We will use these two pieces of information and plug them into the slope-intercept form equation. This will create a linear equation. Let's look at the steps to follow and an example:

__Practice #1__

Determine the equation of the following graph:

Click HERE to check your answer!

__Writing Linear Equations from a Table__

Earlier, you learned how to graph an equation given in slope-intercept form. However, what if you are given a linear equation that is not in slope-intercept form? We have already discussed earlier that slope-intercept form makes it easier to recognize the slope and y-intercept. Hence, we will need to "convert" any linear equation into slope-intercept form. In other words, "solve for y"!

Let's look at an example:

Let's look at an example:

Now we can graph the equation since it is in slope-intercept form!

__Practice #4__

Graph the following equation:

Click HERE to check your answer!

## Quiz

You will take the quiz

CLICK HERE FOR QUIZ

__you have researched and taken notes on slope-intercept form.__**after**CLICK HERE FOR QUIZ

(C) 2017 MATH IN DEMAND