Embed Size (px)
Citation preview
Warm-UpGraph. Then find the slope.
5 minutes
1) y = 3x + 22) y = -2x +5
7.5.1 Equations and Slope7.5.1 Equations and Slope7.5.1 Equations and Slope7.5.1 Equations and SlopeObjectives: •To find the slope and y-intercept of a line from an equation
Find the slope of the line y = 2x - 4.
Slope-Intercept Equation
y = 2x - 4
x y
-4-20
012
-8 -6 -4 -2
2
42 6 8
4
6
-4
-6
-8
-2
8
rise: -4
run: -2rise
sloperun
42
2
The y-intercept is -4.
y = mx + b
Slope-Intercept Equation
slope y-intercept
y = 4x + 8
slope y-intercept= 4
= 8
y = 2x - 3
slope y-intercept= 2
= -3
Find the slope and y-intercept of the line y = -4x + 4.
Example 1
The slope is -4.The y-intercept is 4.
Find the slope and y-intercept of the line y = 5x - 7.
Example 2
The slope is 5.The y-intercept is -7.
Practice
1) y = x + 3
2) y = -4x – 7
3) y = 3x - 9
Find the slope and y-intercept of each line.
Find the slope and y-intercept of the line 3x + 4y = 12.
Example 3
3x + 4y = 12
solve for y-3x -3x
4y = 12 – 3x
4 4
3y 3 x
4
3y x 3
4
slope y-intercept= 334
Practice
1) y = -x - 3
Find the slope and y-intercept of each line.
2) 8x + 2y = 10
3) 3y – 6x = 12
Homework
p.326 #1-10,19-27 odds
7.5.2 Equations and Slope7.5.2 Equations and Slope7.5.2 Equations and Slope7.5.2 Equations and SlopeObjectives: •To graph lines using the slope-intercept equation
Graph y = 3x + 2.
Example 1
-8 -6 -4 -2
2
42 6 8
4
6
-4
-6
-8
-2
8
riseslope
run 3
1
m 3
What is the y-intercept?
What is the slope of this line?
b = 2
Graph
Example 2
-8 -6 -4 -2
2
42 6 8
4
6
-4
-6
-8
-2
8
riseslope
run 4
7
4m
7
What is the y-intercept?
What is the slope of this line?
b = -3
4y x 3
7
Practice
1) y = 3x - 5
Graph each line.
2) y = -2x + 4
3) 3
y x 35
Graph 3x + 4y = 12.
Example 3
3x + 4y = 12
solve for y-3x -3x
4y = -3x + 12
4 43
y x 34
Graph 3x + 4y = 12.
Example 3
3y x 3
4
slopey-intercept
-8 -6 -4 -2
2
42 6 8
4
6
-4
-6
-8
-2
8
Practice
1) 7x + 2y = 4
Graph each line.
2) 5y – 10 = 4x
