224k views
5 votes
X>=-7

Question 9: Lily's bank account has a balance of $620. She withdraws $80
once to pay for her dog's visit to the vet. Then she withdraws $45 every week
to pay the dog sitter. Lily does not make any other withdrawals from this
account, and she does not deposit any money into it. Determine the range of
weeks when Lily will have more than $90 in the account. Write an inequality
to model the situation.

1 Answer

5 votes

Final answer:

After paying the initial vet bill, Lily will have $540 remaining. Calculating weekly withdrawals of $45 to determine when her account drops below $90 results in an inequality, 540 - 45w > 90, which simplifies to w < 10. Thus, she'll have more than $90 for up to 9 weeks.

Step-by-step explanation:

The student is asking to determine the range of weeks Lily will have more than $90 left in her bank account. To model this situation with an inequality, let's denote the number of weeks Lily pays the dog sitter as w. After paying the vet, Lily's account balance is $620 - $80 = $540. Each week she pays $45, so after w weeks, the total amount paid to the dog sitter is 45w. If we want her balance to be more than $90, we set up the inequality 540 - 45w > 90. Solving this inequality gives us:

  • 540 - 45w > 90
  • 540 - 90 > 45w
  • 450 > 45w
  • 10 > w

Lily will have more than $90 in her account for fewer than 10 weeks. Therefore, the range of weeks is from 0 to 9.

User Defiant
by
8.9k points