Essential Question: How do you graph linear equations using point plotting, intercepts, the slope-

intercept form, and the graphing calculator?

In order to graph using point plotting, you will need to create a table.

You will need to choose at least 3 numbers for x and “plug” them into the equation to find corresponding y values.

For Example:Graph y = 2x - 1

x y

Choose x values

“plug” x into the equation

Plot the points

-1 2(-1)-1=-3

0 2(0)-1 = -1

1 2(1)-1 = 1

Graph using point plotting32

1+= xy

x y

-2

0

2

2

1

2

1

2

1

(-2) + 3 = 2

(0) + 3 = 3

(2) + 3 = 4

To graph using intercepts, you will need to find both theX and the y intercept

To find the x-intercept, substitute “0” for y and solve for x

To find the y – intercept, substitute “0” for x and solve for y

For example: y = 4x + 8

X-intercept:0 = 4x + 8 -8 = 4x -2 = x

Y – Intercept:Y = 4(0) + 8 Y = 8

Graph 2x + 3y = 6 using intercepts.

X-intercept:2x + 3(0) = 6 2x = 6 X = 3

Y-intercept:2(0) + 3y = 6 3y = 6 Y = 2

To graph a linear equation, you will need to find the slope and the y-intercept for the equation.

Remember: y = mx + b

slope Y-intercept (the point where the graph crosses the y-axis)

Graph 13

2+= xy Slope =

Y-intercept =

3

2

1

1. Plot the y-intercept

2. Use the slope to find the next point

Slope = “rise over run”

Graph 2x + 5y = 10 using the slope-intercept form: (put the equation in slope-intercept form first)

2x + 5y = 10

5y = 10 – 2x

y = 2 – 2/5 x

slope = -2/5y – intercept = 2

A negative slope means you will go down then right from the y-intercept

Use the link below to access an online graphing calculator:

When using the calculator, you will first need to have the equationin slope-intercept form (y = mx + b)

http://www.coolmath.com/graphit/index.html

Then simply key in the equation and hit EVAL to see the graph

Graph on the graphing calculator42

1+= xy

Graph 3x – 5y = 9 on the graphing calculator. (First you will need to solve for y).

3x – 5y = 9-5y = 9 – 3x

5

9

5

3+

−= xy

Put the above equation into thegraphing calculator and click EVAL

Use the word document link below to access a homework assignment.

Homework

Use the internet link below to access a game you can use to review graphing linear equations.

http://funbasedlearning.com/algebra/graphing/lines/default.htm

Be sure to submit all your work to your teacher when completed!

Good Luck!!