Write and Graph Linear Equation in Slope-Intercept Form

I Can:

1)Write equations in slope-intercept form.

2) Graph equations that are written in slope-intercept form.

Review Slope-Intercept Form• Slope-intercept form is written as:

y = mx + b

• Slope: how slanted a line is• Y-intercept: where the line touches the y-axis

SLOPE Y-INTERCEPT

Use a given slope and y-intercept to write an equation in slope intercept form1) m = 3, b = 4

y = mx + b slope-intercept form

y = 3x + 4 substitute the values given for m and b

2) m = , b = -2

y = mx + b slope-intercept form

y = x – 2 substitute the values given for m and b

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2

Try…

Use the given slope and y-intercept to write the equation in slope-intercept form:

2) m = -2, b = 5

3) m = 6, b = -2

Slope-Intercept Form• The slope-intercept form is a way of writing an equation

y = mx + b

SLOPE Y-INTERCEPT

Identify the slope and y-intercept

1) y = 3x + 4 slope: 3 y-intercept: 4

2) y = – x – 8 slope: – y-intercept: – 8 1

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3) y = – 5x – 9 slope: – 5 y-intercept: – 9

What if the equation is not in slope-intercept form?• Rewrite the equation to fit the form

y = mx + b

Ex) 2x + y = 3 -2x -2x y = -2x + 3

Slope: -2Y-Intercept: 3

Try…

Rewrite the equation in slope-intercept form and identify slope and y-intercept.

4) 3x – 3y = 12

5) x + 4y = 6

Graph Using Slope-Intercept Form 3x + y = 2-3x -3x

Step 1: Rewrite the equation Step 2: Identify slope & y-intercept Step 3: Plot the y-interceptStep 4: Use the slope to find the 2nd point.

x0

y

slope: -3 y-intercept: 2

y = -3x + 2

Try…

Graph using slope-intercept form.

6) -2x – y = 5

7) x + 3y = -9