Download 3.5 Graphing Linear Equations in Slope

3.5 Graphing Linear Equations in Slope-Intercept
Form
Slope is the rate of change between
any two points on a line.
It is the measure of the steepness
of the line.
Equation
Y = -2/3 x + 3
Y = 2x – 2
Y = -x + 1
Y=x-4
Description of Slope of Graph
Graph
Line
-2/3
Y-intercept
3
•Slope = m = rise = change in y = y - y
•run change in x = x - x
•When the line rises from left to right, the slope
is positive.
•When the line falls from left to right, the slope
is negative
Slope in Graphs
• (3, 2) (-3, -2)
(0,2) (2, -1)
Finding slope from a table
X
4
7
10
13
Y
20
14
8
2
X
-1
1
3
5
Y
2
2
2
2
X
-3
-3
-3
-3
Y
-3
0
6
9
Examples continued
X
2
4
6
8
Y
10
15
20
25
X 5 5
Y -12 -9
5
-6
5
-3
Summary of Slopes
• Positive
Negative
Zero
Undefined
Slope-Intercept Form
•A linear equation written in the form y = mx + b is
in slope intercept form.
•The slope of the line is m, and the y-intercept is b.
•Y = mx + b
Examples: Find the slope and y-intercept
•Y = 3x – 4
y = 6.5
-5x – y = -2
Graph
•Graph 2x + y = 2