Big Ideas Math: Modeling Real Life, Grade 8
BI
Big Ideas Math: Modeling Real Life, Grade 8 View details
3. Linear Functions
Continue to next subchapter

Exercise 9 Page 293

Identify the y-intercept. Then, we will use the Slope Formula to find the slope.

y=3

Practice makes perfect

Equations written in slope-intercept form follow a specific format. y= mx+ b In this form, m is the slope and b is the y-intercept. We need to identify these values using the graph.

y-intercept

The y-intercept is the y-value where the line crosses the y-axis.

We can see that the function intercepts the y-axis at (0, 3). This means that the value of b is 3. y= mx+ 3

Slope

To find the slope, we will use the Slope Formula. m = y_2-y_1/x_2-x_1 Observing the given graph, we can see that the line passes through the points (0,3) and (2,3). Let's substitute these points into the Slope Formula to find m.
m = y_2-y_1/x_2-x_1
m=3- 3/2- 0
Simplify right-hand side
m=0/2

0/a=0

m=0

Writing the Equation

Now that we have the slope and the y-intercept, we can write our final equation. y= 0x+ 3 ⇔ y= 3