Marcos purchases a top-up card for his pre-paid cell phone. His remaining balance, B, can be modeled by the equation B=40−0.1n, where n is the number of minutes he's talked since purchasing the card.

a) How much money was on the card when he purchased it? $______. Which intercept is this? B-intercept or N-intercept?

b) How many minutes will he have talked when he runs out of money? $_____. Which intercept is this? B-intercept or n-intercept ?

c) What is the slope of this equation?________ . What are the units on the slope? Minute , dollars per minute ,minutes per dollars or dollars ?

Marcos purchases a topup card for his prepaid cell phone His remaining balance B can be modeled by the equation B4001n where n is the number of minutes hes talk class=

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Answer:

Part a) When Marcos purchased the card, the balance on the card was $40

This is the B-intercept

Part b) Mark will have spoken 400 minutes when he runs out of money

This is the n-intercept

part c) The slope of the equation is -0.1 and the units are dollars per minute

Step-by-step explanation:

we have

[tex]B=40-0.1n[/tex]

where

B is balance in dollars on the card

n is the number of minutes

Part a) How much money was on the card when he purchased it? $______. Which intercept is this? B-intercept or N-intercept?

we know that

The B-intercept is the value of B when the value of n is equal to zero

so

For n=0

substitute and find the value of B

[tex]B=40-0.1(0)=\$40[/tex]

therefore

When Marcos purchased the card, the balance on the card was $40

This is the B-intercept

Part b) How many minutes will he have talked when he runs out of money? $_____. Which intercept is this? B-intercept or n-intercept ?

we know that

The n-intercept is the value of n when the value of B is equal to zero

so

For B=0

substitute and find the value of n

[tex]0=40-0.1n[/tex]

[tex]0.1n=40[/tex]

[tex]n=400\ minutes[/tex]

therefore

Mark will have spoken 400 minutes when he runs out of money

This is the n-intercept

Part c) What is the slope of this equation?________ . What are the units on the slope? Minute , dollars per minute ,minutes per dollars or dollars ?

we have

[tex]B=40-0.1n[/tex]

This is is the equation of the line into slope intercept form

[tex]m=-0.1\frac{\$}{minute}[/tex] -----> slope of the equation

[tex]b=40[/tex] ------> the B-intercept

The units of the slope are dollars per minute