Lily is saving up to buy a cellphone. She needs to save at least $300 before she is able to buy the phone. Her grandfather gives her $40, and she earns $65 tutoring after school each week. Write an inequality for the number of weeks Lily will need to save to have at least $300, and describe the solutions.(2 points) x+ ≥ , where x is the number of weeks Lily will need to save. Lily must save for at least weeks to have at least $300.

1 answer

To create an inequality for the number of weeks Lily will need to save, we start by noting her initial amount and her earnings per week.

  1. Lily starts with $40 from her grandfather.
  2. She saves $65 each week from tutoring.

We want to find the minimum number of weeks, represented by \( x \), that she needs to save to have at least $300.

The total amount Lily will have after \( x \) weeks is: \[ 40 + 65x \]

We need this total to be at least $300, so we can write the inequality as: \[ 40 + 65x \geq 300 \]

Next, we will solve the inequality for \( x \):

  1. Subtract 40 from both sides: \[ 65x \geq 300 - 40 \] \[ 65x \geq 260 \]

  2. Divide both sides by 65: \[ x \geq \frac{260}{65} \] \[ x \geq 4 \]

Thus, the inequality is: \[ x \geq 4 \]

Description of the solutions: The solution to this inequality means that Lily must save for at least 4 weeks in order to have enough money, which includes the initial $40 given by her grandfather and her earnings from tutoring. If \( x = 4 \), she will have exactly $300, while any value greater than 4 represents a situation where she has more than $300 saved.