To write an inequality for the number of weeks \( x \) that Lily will need to save, we can start by considering her initial amount and her weekly earnings.
- Initial amount from her grandfather: $40
- Weekly earnings from tutoring: $65
- Total amount needed to buy the phone: $300
After \( x \) weeks of tutoring, the total amount of money Lily will have is the initial amount plus the money she earns from tutoring.
This can be expressed as: \[ 40 + 65x \]
We want this amount to be at least $300. Therefore, we can set up the inequality: \[ 40 + 65x \geq 300 \]
Now, we can simplify this inequality to find the number of weeks \( x \) that Lily needs to save:
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Subtract 40 from both sides: \[ 65x \geq 300 - 40 \] \[ 65x \geq 260 \]
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Divide both sides by 65: \[ x \geq \frac{260}{65} \] \[ x \geq 4 \]
Thus, the final inequality is: \[ x + 4 \geq 0 \] (fill in \( x + 4 \), but expression is differentiated. We need \( x \geq 4 \)).
Summary:
- The correct inequality for the number of weeks is: \[ 65x + 40 \geq 300 \]
- The solution to this inequality is: Lily must save for at least 4 weeks to have at least $300.