Download 4.6 Slope Intercept Form Word Problems

Goals:
Graph and interpret equations in slopeintercept form that model real life situations.
Use a graphing calculator to graph linear
equations.
Eligible Content:
A1.1.2.1.1 / A1.1.2.1.3 / A1.2.1.1.1 / A1.2.1.2.1
A1.2.1.2.2 / A1.2.2.1.3 / A1.2.2.1.4
 Slope
is rate of change
 y-intercept
is the beginning amount
Find the y-intercept and
tell what it reveals about
the situation.
Cookies
The graph shows the
number of cookies left on
a plate after time has
passed at a party.
Find the slope and tell
what it reveals about the
situation.
22
20
18
16
14
12
10
8
6
4
2
0
0
2
4
6
8
Time (in minutes)
10
 The
equation h = ½ t + 24 models
changing river heights. h represents the
height of the river (in feet) and t
represents the time (in hours) since the
flooding began.
• What does the slope of the equation reveal about
this situation?
• What does the y-intercept of the equation reveal
about this situation?
 The
equation s = 15t + 25 models
changing speeds of a car as it enters an
expressway. s represents the speed of
the car (in miles per hour) and t
represents the time (in minutes).
• What does the slope of the equation reveal about
this situation?
• What does the y-intercept of the equation reveal
about this situation?
Equations must be in slope intercept form.
 Press Y= button
 Type in equation
 Press GRAPH button
 To change the x and y axes press
WINDOW
Graph each equation on your calculator:
1. y = 3x + 4
2. y = -5x + 7
3. 2x + y = 8
4. 3x – 2y = 10
Graph each of the word problems from
earlier in class:
 River: y
 Car: y
= ½ x + 24
= 15x + 25
 None
