Question

1. Call Wireless phone company charges $0.50 for the first call you make and $0.10 for each additional minute. The cost of a phone call can be expressed by the formula C = 0.50 + 0.10(m – 1), where C is the total cost in dollars and m is the number of minutes that you talk. If the bill for your phone call was $1.90, how long did you talk?
A.
12 minutes
B.
14 minutes
C.
15 minutes
D.
16 minutes
2. You spend $77 shopping. You buy some shirts at $12 each, and spend $5 on food. How many shirts did you buy?
A.
5x + 12 = 77
B.
x(12 + 5) = 77
C.
12x + 5 = 77
D. 12 X 5+x=77

Answer 1

For #1 we can plug in 1.90 into the equation:

1.90 = 0.50 + 0.10(m - 1)

Distribute 0.10 into the parenthesis:

1.90 = 0.50 + 0.10m - 0.10

Simplify:

1.90 = 0.40 + 0.10m

Subtract 0.40 to both sides, what's 1.90 - 0.40? @courtney-ray

Answer 2

1.5

Answer 3

and and with number 2?

Answer 4

That's not your answer yet..we get:

1.5 = 0.10m

Now we divide 0.10 to both sides, what's 1.5 / 0.10?

Answer 5

@courtney-ray

Answer 6

it was 15

Answer 7

all i had to do was take out the decimal

Answer 8

Yep, 15 is your answer for #1.

Answer 9

Now for #2 '5' will be by itself since it's a 1-time thing, and 12 will have a variable because that's the price PER shirt, and the variable will represent the # of shirts you buy.

Then we will have = 77 because that's the amount you spent.

So which one looks most like this? @courtney-ray

Answer 10

its B

Answer 11

No, B will put a variable on 5 too, but we don't want a variable on 5, we just want it to be alone.

Answer 12

well i entered B and it said it was right

Answer 13

Oh..well actually it should be C..

Answer 14

12x + 5 = 77

Subtract 5 to both sides:

12x = 72

Divide 12 to both sides:

x = 6

So you bought 6 shirts..

Check:

12(6) + 5 = 77

72 + 5 = 77

77 = 77

Answer 15

x(12 + 5) = 77

Distribute 'x' into the parenthesis:

12x + 5x = 77

Add 12x + 5x:

17x = 77

Divide 17 to both sides:

x = 4.52941176

You can't buy 4.52941176 shirts..so B is obviously wrong..