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

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 $3 G $6 H $15 J $24 K $32 1st week + 2nd week + 3rd week + 4th week Average = 4 $17.50 + $23.50 + $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

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 $4.50 G $6.48 H $7.30 J $7.50 K $8.75 The answer is 7.5! Total Selling price + Tax (Selling price) = Note: Tax = 8% = 0.08 $8.10 = X + 0.08X 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

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 $23 G $33 H $49.50 J $51 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

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