Marissa wants to buy a DVD player that runs for at least 150 dollars she already saved $80 and plans to save an additional $10 each week run in quality that represents this

Price of DVD player ≥ $150

Saved = $80

Amount needed = $150 - $80 = $70

Saving per week = $10

Let x be the number of weeks needed:

80 + 10x ≥ 150

10x ≥ 150 - 80

10x ≥ 70

x ≥ 70 : 10

x ≥ 7

Answer: She needs to save for for at least 7 weeks.