Question

A prepaid cell phone company charges $20 per month plus an additional $0.04 per minute for all calls.

How much will it cost to use 275 minutes in one month?
How much will it cost to use 700 minutes in one month?
Write an algebraic expression to represent the total cost.

Answer 1

d

Explanation:

Answer 2

Part a)
`y=0.04x+20`

Part b) The total cost is $31

Part c) The total cost is $48

Explanation:

Part a) Write an algebraic expression to represent the total cost

Let

x -----> the number of minutes for all calls in a month

y ----> the total cost in dollars per month

we know that

The linear equation in slope intercept form is equal to

`y=mx+b`

where

m is the slope or unit rate of the linear equation

b is the y-intercept or initial value of the linear equation

In this problem we have

The unit rate or slope is equal to

`m=\$0.04\ per\ month`

The initial value or y-intercept (value of y when the value of x is equal to zero) is

`b=\$20`

substitute

`y=0.04x+20`

Part b) How much will it cost to use 275 minutes in one month?

For x=275 minutes

substitute the value of x in the linear equation and solve for y

`y=0.04(275)+20`

`y=31`

therefore

The total cost is $31

Part c) How much will it cost to use 700 minutes in one month?

For x=700 minutes

substitute the value of x in the linear equation and solve for y

`y=0.04(700)+20`

`y=48`

therefore

The total cost is $48