Ellie is saving to buy a phone. she wants to have at least $299 saved before buying one. she currently has $213 saved, and she receives $10 a week as an allowance from her parents. after how many weeks will ellie have enough money saved? Ellie writes the inequality 10w+213 299, where w is the number of weeks, to help figure this out. solve her inequality

1 answer

To solve Ellie's inequality \(10w + 213 \geq 299\), we will isolate \(w\).

Here are the steps:

  1. Subtract 213 from both sides: \[ 10w \geq 299 - 213 \] \[ 10w \geq 86 \]

  2. Divide both sides by 10: \[ w \geq \frac{86}{10} \] \[ w \geq 8.6 \]

Since \(w\) represents the number of weeks, and it must be a whole number, we round up to the next whole number, which means Ellie will need at least 9 weeks.

Thus, Ellie will have enough money saved in 9 weeks.