View All Pages

LEI - Graphing Lines (Lesson)

algebra_Lesson_Top.png

Graphing Lines

Graphing Lines Information 

Graphing Horizontal and Vertical Lines Practice

Match the equation of each line to the appropriate graph.

1.Slide1.jpg 2.Slide2.jpg 3. Slide3.jpg

4.Slide4.jpg 5. Slide5.jpg 

TO VIEW THE SOLUTIONS ONCE YOU HAVE PRACTICED, CLICK HERE. Links to an external site.

Lines can be written in two forms:

Slope-intercept: y = mx + b

Standard: Ax + By = C

Graphing Lines by Making a Table

Like we did in the cell phone problem, we can graph lines by using a table. In order to graph a line, you always need 2 points! Let's plugin values for x, the independent variable, to find what y is the output. When we are working with graphs, we often use x and y rather than x and f(x). But the important thing to remember is that f(x) and y both represent the OUTPUT! 

Example: 2x + y = 7

But first, we need to know how to graph lines!

Input (x)

Substitute for x and solve for y

Write your ordered pair

(input, output)
1

2(1) + y = 7

2 + y = 7

y = 5

 (1, 5)
4

2(4) + y = 7

8 + y = 7

y = -1

 (4, -1)

Ordered Pairs Practice

Graph with points and lines Use the equation to complete the ordered pairs below:

3x + y = 9

  1. ( ____, 6)  
  2. (2, _____) 
  3. (1/3, _____) 

Use the graph to complete the ordered pairs below:

  1. (____, -2) 
  2. (3, ____) 
  3. (4, ____) 
  4. What is the slope of the line? 

TO VIEW THE SOLUTIONS ONCE YOU HAVE PRACTICED, CLICK HERE. Links to an external site.

Graphing Lines by Finding X - and Y - Intercepts

Graphing lines using x and y intercepts graph 

Example: Find the x- and y- intercepts of 2x + y = 7.

x intercept explanation y intercept explanation 

Another example of how to plot points and then create a line through it. 

Graphing by Finding Slope and Y-Intercept

In Slope-Intercept form, y = mx + b, m is the slope and (0, b) is the y-intercept.

Example:

 y = -(3/2)x - 4

slope: -(3/2)

y - intercept: (0, -4)

Use that information to graph the line:

Step 1, plot your y-intercept. Step 2, use the slope to find another point. Step 3, graph your line. 

Watch this video for examples of equations in standard form:

 

Slope and Intercepts Practice

  1. Find the x and y intercepts: 2x - 5y = 10
  2. Find the x and y intercepts: -2x + y = 6
  3. Find the x and y intercepts: y = -2x + 4
  4. Find the x and y intercepts: 3x + 8y = -24
  5. Find the x and y intercepts: x + 2y = 10
  6. Find the slope and y intercept: y = 2x - 7
  7. Find the slope and y intercept: 2x + y = 5
  8. Find the slope and y intercept: y = -2x + 7
  9. Find the slope and y intercept: y = 1/2x - 7
  10. Find the slope and y intercept: x + 2y = 10

TO VIEW THE SOLUTIONS ONCE YOU HAVE PRACTICED, CLICK HERE. Links to an external site.

ALGEBRA_LessonBottom.png

IMAGES CREATED BY GAVS