Question

#6) Beth saved a total of $30 per month for her first car. Beth saved

money for 20 months and opened her account with $100. What is the

domain and range of the situation representing the amount of money

Beth saved in respect to time she saved? Write your answer in

interval notation.

D:




R:

Answer 1

Domain = 0≤m≤20 for mEZ+

Range = $100≤A≤$700 for all values of m

Explanation:

Initial amount in the account = $100

Amount saved by beth monthly = $30

Amount in the bank after X month = $100+$30X where X is the number of months beth intend to save up to.

The amount in her bank in her first month = $100+$30(1)

= $100+$30

= $130

Amount saved in the second month will be when X = 2

= $100+$30(2)

= $100+$60

= $160

The amount in the bank will keep increasing by $30 monthly until the 20month.

The amount he will have in her bank in the 20th month will be at when X = 20

= $100+30X

= $100+30(20)

= $100+$600

= $700

This means that her money will be $130 in the first month and will keep increasing until it reaches $700 in the 20th month.

The DOMAIN will be the interval of the time she used in saving. Since she saved for 20months, the domain will be expressed as 0≤m≤20 for mEZ+ where m is the number of month she uses to save.

The Range will represent the amount she saved within the specified time and will be expressed as $100≤A≤$700 for all values of m.

Where $100 is the amount in the account initially and $700 is the amount in the account after 20 months.