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 wis the number of weeks, to help figure this out. Solve her inequality.
w ≥ 8.6
w ≥ 860
w ≥ 51.2
w ≥ 86
To solve the inequality 10w + 213 ≥ 299, we first subtract 213 from both sides of the inequality:
10w ≥ 299 - 213
10w ≥ 86
Then, we divide both sides of the inequality by 10:
w ≥ 86 / 10
w ≥ 8.6
Therefore, Ellie will have enough money saved after 8.6 weeks. However, since we can't have a fraction of a week, we round up to the nearest whole number. This means that Ellie will have enough money saved after 9 weeks.
So, the correct answer is: w ≥ 9