INTERPRET LINEAR GRAPHS

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INTERPRET LINEAR GRAPHS WRITE LINEAR EQUATIONS
SECTION 5.4C
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You can use a table of values for a linear
equation to get information about that
equation. Example1 A. The table below shows
the amount that a company charges for bicycle
rental for up to 8 hours. An initial deposit is
included in the amounts. Without graphing the
points write an equation for the function.
Time in hours, X Rental cost in dollars, Y
1 12
2 16
3 20
4 24
5 28
6 32
7 36
8 40
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Find the slope
Time in hours, X Rental cost in dollars, Y
1 12
2 16
3 20
4 24
5 28
6 32
7 36
8 40
Find the y-intercept
Use m, x, and y to find b.
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1
Pick ANY point from the table.
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Find the slope
Time in hours, X Rental cost in dollars, Y
1 12
2 16
3 20
4 24
5 28
6 32
7 36
8 40
Find the y-intercept
Use m, x, and y to find b.
4
1
Pick ANY point from the table.
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Time in hours, X Rental cost in dollars, Y
1 12
2 16
3 20
4 24
5 28
6 32
7 36
8 40
Pick ANY point from the table.
4
1
6
The water in a river was a certain level before
it started to recede at a constant rate. The
table below shows the water level after a certain
number of days. Without graphing the points write
an equation for the function. In how many days
will the water level be 26 feet?
Time in days, x Water level in feet, y
2 33
4 32
6 31
8 30
10 29
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Without graphing the points write an equation for
the function.
Pick ANY point from the table.
Find the slope
Time in days, x Water level in feet, y
2 33
4 32
6 31
8 30
10 29
-1
2
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The water in a river was a certain level before
it started to recede at a constant rate. The
table below shows the water level after a certain
number of days. Without graphing the points write
an equation for the function. In how many days
will the water level be 26 feet?
Time in days, x Water level in feet, y
2 33
4 32
6 31
8 30
10 29
If y 26 feet, what is x?
16 days
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C. Kim, a skater, pays an initial fee for
membership at the rink, plus a certain amount per
hour that she practices. A graph shows that
after 3 hours of skating the total cost is 57.
It also shows that after 5 hours of skating the
total cost is 65. Write an equation to model
this situation.
Time in hours, x Total cost in dollars, y


3
57
Pick ANY point from the table.
8
2
5
65
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Quite often you will be given two points on a
line and asked to write the linear equation.
1. Find the slope. 2. Substitute the
values for the slope and x and y. 3. Find
the value of the y-intercept. 4. Write your
equation in slope intercept form.
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Example 2 Write an equation in slope-intercept
form for the line containing the two points.
A.
Pick EITHER point for x and y.
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Example 2 Write an equation in slope-intercept
form for the line containing the two points.
B.
Pick EITHER point for x and y.
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Example 2 Write an equation in slope-intercept
form for the line containing the two points.
C.
Pick EITHER point for x and y.
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Example 2 Write an equation in slope-intercept
form for the line containing the two points.
D.
Pick EITHER point for x and y.
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Example 2 Write an equation in slope-intercept
form for the line containing the two points.
E.
Pick EITHER point for x and y.