Unit Test:
Answer the questions below. When you are finished, submit this assignment to your teacher by the due date for full credit.
(10 points)
1. Allegra has a cell-phone plan that charges $65 per month and $0.10 for every minute that she uses the phone beyond what her plan allows. One month, she was billed $73.40.
a. Define a variable for the unknown.
b. Write an equation to model the problem. Explain your answer.
c. Solve the equation. Show your work.
d. Find the number of minutes that Allegra went over the time that the plan allows. Explain your answer.
Answer:
A) How many minute she went over the bill.
B) $73.40=$65+1/10x
C) 73.40 – 65 = 65 – 65 + 1/10x 8.40 x 10 = 1/10x x 10 x = 84
(5 points)
2. Andrea wants to deposit money into a bank account that earns 4% simple interest. Use the formula to find the amount of money that she should deposit so that she earns $2800 after 3.5 years. Show and explain your work.
Answer:
2800 = (P) (0.04) (3.5)
2800/3.5/0.04 = P
P = 20000
(7 points)
3. Solve the equation and write the solution set.
|4x – 8| – 3x = 6x + 2
Answer:
|4x-8| -3x = 6x+2
4x-8=9x+2
-8=5x+2
-10=5x
-10/5=5x/5 x=-2 |4x-8| -3x = 6x+2
|4x(-2)-8|-3(-2)=6(-2)+2
|-8-8|-(-6)= -12+2
| -16|-(-6)= -10
| -16| +6= -10
| -10| = -10
10 = -10