Lesson 22 - SLOPE-INTERCEPT METHOD
Example 1
a. Complete the table below and graph the linear
equation 𝑦 = 2𝑥 + 3,
x
y = 2x + 3
y
b.
Find the slope of the line using the slope formula.
c.
Compare the original equation to your answer in part (b).
What can you conclude from your observation of the
equation and your slope answer? _________________________________
____________________________________________________________________________
d.
Identify the point where the linear function, 𝑦 = 2𝑥 + 3, intersects the y-axis. (______,_____)
This point is called the _____________________________
GRAPHING AN EQUATION USING THE SLOPE-INTERCEPT METHOD
Graph the equation 𝑦 = 2𝑥 + 3 using the slope-intercept method.
1. Write the equation in y=mx ± b form.
2. Identify the slope, m (as a fraction) and the y-intercept, b.
m = __________ b = (____,____)
3. Plot the y-intercept. This point is always on the y-axis!!!
4. Use the slope found in step 2 to rise (the numerator)
and run (the denominator). Repeat the process until there
is no more graph paper.
6. Connect the points to create a straight line.
7. Label the line with the original equation.
Compare the two graphs on this page. What do you notice?
____________________________________________________
Example 2
Graph the linear equation 𝑦 = −3𝑥 − 5, using the slope-intercept
method.
m = __________
b = (____,____)
Example 3
Use the observations you made in examples 1 and 2 to determine the slope of the graph of the
equation 𝒚 = 𝟓𝒙 − 𝟒. (Do not graph this equation)
m = __________ b = (____,____)
Example 4
Use the observations made in examples 1 and 2 to determine the slope of the graph of the linear
𝟑
equation 𝒚 = − 𝒙 + 𝟔. (Do not graph this equation)
𝟒
m = __________
b = (____,____)
ON YOUR OWN
Graph the linear functions in examples 3 and 4 using the slope-intercept method.
3.
4.
What quadrant does this line never enter? ____
What quadrant does this line never enter? ___
Challenge: Write the following equation in slope-intercept form. Hint: Use your algebra skills from Unit 1.
8x + 2y = -10