5.3 Slope-intercept form

Identify slope and y-intercept of the graph & graph an equation in slope-intercept

form. day 2

Write an equation of the line in slope-intercept form that passes through the points (2,1) and (5,-8).

y = mx + b

m =b =

(x1, y1) (x2, y2)

m = ___-___ -

-8 15 2

= -93

= -3 -3

y = mx + bSolve for b: x =

y = 12

1 = -3( 2) + b1 = -6 + b7 = b

7

y = -3x + 7

Write an equation of the line in slope-intercept form that passes through the points (-3,4) and (2,-1).

y = mx + b

m =b =

(x1, y1) (x2, y2)

m = ___-___ -

-1 42 -3

= -55

= -1 -1

y = mx + bSolve for b: x =

y = 4-3

4 = -1( -3) + b4 = 3 + b1 = b

1

y = -1x + 1

y = mx + b

y = ¾x + 1

Steps to graph an equation in slope-intercept form.

1. Identify m and b

m =

b =

¾1

2. Put the y-intercept (b) on the y-axis.

3. Use your slope to get to the next point.

Rise ---if positive: go up; if negative: go down

Run--- go to the right

4. Connect the points.

y = mx + b

y = 3x

Steps to graph an equation in slope-intercept form.

1. Identify m and b

m =

b =

3=0

2. Put the y-intercept (b) on the y-axis.

3. Use your slope to get to the next point.

Rise ---if positive: go up; if negative: go down

Run--- go to the right

4. Connect the points.

3

1

y = mx + b

y = 4

Steps to graph an equation in slope-intercept form.

1. Identify m and b

m =

b =

04

2. Put the y-intercept (b) on the y-axis.

3. Use your slope to get to the next point.

Rise ---if positive: go up; if negative: go down

Run--- go to the right

4. Connect the points.

y = mx + b

y = -1x + 4

Write an equation in slope-intercept form.

1. Identify m and b

m =

b =

-14

Or y = -x + 4

Assignment: page 312: 22-34,37-39, 48,49

Note: 27: will have a decimal for the y-intercept