Lesson 5.1Write Equations in

Slope-Intercept Form

Write 3x + 4y = 24 in slope-intercept form:

• Remember slope-intercept form is y = mx + b

• 3x + 4y = 24-3x -3x

• 4y = -3x + 24 4 4 4

• y = -3/4x + 6

y = -3/4x + 6

• What is the slope?

• -¾• What is the

y-intercept?

• 6

• Write the equation of a line whose slope is -3/4 and whose y-intercept is 6.

• Start with the formula:y = mx + b

• Substitute in your values.

• y = -3/4x + 6

Try it again…

• Write the equation of a line whose slope is -2 and whose y-intercept is -5.

• y = -2x – 5• Write the equation of a line whose slope

is 9 and whose y-intercept is 1.• y = 9x + 1• Write the equation of a line whose slope

is -2/7 and whose y-intercept is -8.• y = -2/7x - 8

Study the graph below. Write the equation of this line

in slope-intercept form.

-4

-2

-6

4

6

2

2 4 6-6 -4 -2

What is the slope?

What is the y-intercept?

Up 4 over 2 = 4/2 = 2

2

6

The equation of this line is:

y = 2x + 6

Study the graph below. Write the equation of this line

in slope-intercept form.

-4

-2

-6

4

6

2

2 4 6-6 -4 -2

What is the slope?

What is the y-intercept?

-1

-2

The equation of this line is:

y = -x - 2