Transcript 09IM_C2_L08

Objectives
Example 1
Example 2
Example 3
Quick Quiz
• To recognize linear relationships in a variety of
representations
• To translate from one representation to another
• To explain the connection between the constant
difference, the slope of the graph, and the
symbolic representation of the relationship (the
a in y = ax+ b)
• To determine b in the rule y = ax + b from a
graph
INTEREST The table shows
the amount of interest $3,000
would earn after 7 years at
various interest rates. How
much interest would $3,000
earn at 6 percent interest?
Understand
You know the amount of interest
earned at interest rates of 1%, 2%,
3%, 4%, and 5%. You want to know
the amount of interest earned at 6%.
Plan
Look for a pattern in the amounts of
interest earned. Then continue the pattern
to find the amount of interest earned at a
rate of 6%.
Solve
For each increase in interest rate, the
amount of interest earned increases by
$210. So for an interest rate of 6%, the
amount of interest earned would be
$1,050 + $210 = $1,260.
Answer: The amount of interest at 6 percent is $1,260.
Check
Check your pattern to make sure the
answer is correct.
INTEREST The table below
shows the amount of interest
$5,000 would earn after 3 years
at various interest rates. How
much interest would $5,000
earn at 7 percent interest?
A. $800
B. $900
1.
2.
3.
4.
C. $1,000
0%
D
0%
C
0%
B
D. $1,050
A
0%
A
B
C
D
MUSIC During a clearance sale, a music store is
selling CDs for $3 and tapes for $1. Graph the
function 3x + y = 6 to find how many CDs and tapes
Bill can buy with $6.
First, rewrite the equation by solving for y.
3x + y = 6
3x – 3x + y = 6 – 3x
y = 6 – 3x
Write the equation.
Subtract 3x from each side.
Simplify.
Choose values for x
and substitute them to
find y. Then graph the
ordered pairs.
Answer: The solutions are
0 CDs and 6 tapes,
1 CD and 3 tapes, or
2 CDs and 0 tapes.
BAKE SALE During a bake sale, a plate of brownies
is sold for $2 and a plate of cookies is sold for $1.
Graph the function 2x + y = 4. Which is not a
combination of plates of brownies and cookies Craig
can buy with $4?
A. 2 plates of brownies,
0 plates of cookies
B. 1 plate of brownies,
2 plates of cookies
C. 1 plate of brownies,
3 plates of cookies
D. 0 plate of brownies,
4 plates of cookies
1.
2.
3.
4.
0%
0%
A
B
A
B
C
D
0%
C
0%
D
MOVIE RENTAL A movie rental
store charges $4 to rent a
movie. If a movie is returned
late, the charge is $3 extra per
day. The total cost is given by
the equation y = 3x + 4 where x
is the number of days the
movie is late. Is the total cost
proportional to the number of
days the movie is late? Explain.
Compare the ratio of total cost to
number of days late.
Answer: The total cost is not proportional to the
number of days late.
GAME RENTAL A game rental
store charges $5 to rent a game.
If a game is returned late, the
charge is $5 extra per day. The
total cost is given by the
equation y = 5x + 5, where x is
the number of days the game is
late. Use the graph to find how
many days late a game is if the
late charge is $10.
D. 4 days
0%
0%
C
C. 3 days
A
0%
A
B
C
D
0%
D
B. 2 days
B
A. 1 day
1.
2.
3.
4.
A. Determine whether the table has a linear
relationship. If so, write its symbolic rule.
A.
B.
0%
B
D. nonlinear
A
0%
0%
C
C.
A
B
C
D
0%
D
1.
2.
3.
4.
B. Determine whether the table has a linear
relationship. If so, write its symbolic rule.
A. linear; y = –8x + 16
B. linear; y = 8x + 16
A
B
C
D
0%
C
0%
B
0%
A
D. nonlinear
1.
2.
3.
4.
0%
D
C. linear; y = 8x –16
C. Determine whether the table has a linear
relationship. If so, write its symbolic rule.
A. linear; y = x – 3.7
B. nonlinear
1.
2.
3.
4.
0%
C
0%
B
0%
A
D. linear; y = x + 3.7
0%
D
C. linear; y = –x + 3.7
A
B
C
D
Image Bank
Math Tools
Multilingual e-Glossary
Slope and Intercept