Warm upsGraph using intercepts:

1. 2x + 3y = 12 2. 4x – 5y = 20

3. 2x – y = -4 4. 3x + 4y = -8

Convert Standard to Slope-Intercept

Objective: To convert a linear equation from standard form to

slope-intercept form.

2x + 3y = 12

What is the slope? _____

Part of being able to analyze a graph is being able to say the slope.

Also, sometimes it is easier to graph with the slope and y-intercept than with the x-and y-intercept.

Writing an equation from a graph is easier to do with slope and y-intercept (y = mx + b) You will have to do this on your test!

-2/3

Convert

Standard Slope-Intercept

Steps:1. Subtract Ax

2. Divide everything by B

Ax + By = C y = mx + b

Example 1

Convert the equation from standard form to slope-intercept form:

2x + 3y = 12

-2x -2x

3y = -2x + 12

3 3 3

x+4

Ax + By = C Steps:

1. Subtract Ax

2. Divide everything by B

Example 2

Convert the equation from standard form to slope-intercept form:

2x – y = -4

-2x -2x

-y = -2x – 4

-1 -1 -1

y = 2x + 4

Ax + By = C Steps:

1. Subtract Ax

2. Divide everything by B

Convert to slope-intercept form:

4x – 5y = 10

Now, identify the slope and y-intercept: (hint: slope is m, y-intercept is b)

Slope:______

y-intercept:_______

y = 4/5x – 2

4/5

-2

In General

Ax + By = C y = -a x + c

b b

m = -a/b

y-intercept = c/b

5x + 2y = 12 -5x -5x 2y = -5x + 12 2 2 2

y = -5/2x + 6

Slope:______ y-intercept:_______

y = -5/2x + 6

-5/2

6

Identify slope and y-intercept: