1. Fixed charge: $25 Varying charge: $40 for each hour
8-A)A mechanic charged a customer $25 for parts, plus $40 for each hour he worked. The bill totaled $325. About how long did the mechanic work on this customer’s car?
F) 5 h G) 7.5 h H) 8.75 h J) 11.4 h K) 13 h
Fixed charge: $25 Varying charge: $40 for each hour
Total = Fixed charge + Varying charge
$325
= $25 + $40X Where X is # of hours
we use a TI-82 to find the value of x
Enter the right side in Y1 and left
side in Y2 :
3) Press 2nd GRAPH and enter the
Answer choices in x column. The
Answer will make the left side equal to the right side.
The answer is 7.5!
2) Press 2nd WINDOW
and set the Indpnt: to ASK:
OBJECTIVE 8

2. 8-B) Kelly earned $17.50, $23.50, and $16 mowing lawns on 3 consecutive weeks. Her goal was to earn an average of at least $18 per week. What is the minimum she should earn during the fourth week to meet her goal?
F $ G $ H $ J $ K $32
1st week +
2nd week +
3rd week +
4th week
Average = 4
$ $ $16 + X
We want to find the value of x or how much Kelly has to earn in order to make at least an average of $18 For the 4 weeks. We will use a TI-82 to do so.
$18 = 4
1) Enter the right side in Y1 and left side
inY2:
3) Press 2nd GRAPH and enter the answer
choices in x column. The answer will make
the left side equal to the right side.
The answer is 15!
2) Press 2nd WINDOW and set the Indpnt:
to ASK:
OBJECTIVE 8

3. Selling price + Tax (Selling price) = $8.10 = X + 0.08X
8-C)Matilda paid a total of $8.10 for a belt, including tax. If the tax rate was 8% , what was the selling price of the belt?
F $ G $ H $ J $ K $8.75
The answer is 7.5!
Total
Selling price + Tax (Selling price) =
Note:
Tax = 8% = 0.08
$8.10 = X X
We want to find the value of x or the selling price. We will use a TI-82 to do so.
1) Enter the right side in Y1 and left side
inY2:
3) Press 2nd GRAPH and enter the answer
choices in x column. The answer will make
the left side equal to the right side.
2) Press 2nd WINDOW and set the Indpnt:
to ASK:
OBJECTIVE 8

4. We let Money Peggy spent = X, then we have:
8-D)Donna and Peggy went shopping and spent $84 altogether. Donna spent $15 less than twice as much as Peggy. How much did Donna spend?
F $ G $ H $ J $ K $54
Total =
Money Donna spent +
Money Peggy spent
Use X to find:
$ Donna=
2(33)-15=51
We let Money Peggy spent = X, then we have:
Money Donna spent =
Twice the Money Peggy spent - 15
= 2X - 15
We want to find the value of x or how
much Peggy
spent. We use this value to find how much Donna spent. We will use a TI-82 to do so.
Total =
X +
(2X – 15)
So, we have:
$84 = X + (2X – 15)
1) Enter the right side in Y1 and left side
inY2:
3) Press 2nd , TRACE, 5, and ENTER 3 times to find the value of X or the solution of the equation.
2) Press GRAPH. Then, ZOOM, 3, and ENTER. You need to zoom out three times to see the intersection point
The value of X is 33!
OBJECTIVE 8

5. Adapted by Rene Patterson
End-of-Course Test
Algebra I
THIS IS THE END OF OBJECTIVE 8 REVIEW. YOU NEED TO WORK OUT THE PROBLEMS RELATED TO THIS OBJECTIVE. YOUR TEACHER WILL PROVIDE YOU WITH THE WORKSHEETS. WE WILL COVER OBJECTIVE 9 NEXT.
CREATED BY R.KHADEM
Adapted by Rene Patterson