Warm up

1. Warm up • Luc received $50 from his grandparents for his birthday. He makes $75 each week as a cashier at the supermarket. Since his birthday, he has saved more than enough money to buy a game system that costs $450. • 1. How many weeks ago was Luc’s birthday? • 2. After purchasing the game system, will Luc have any money left over? How do you know? 50 + 75w > 450 75w > 400 w > 5.3 Luc is paid for whole weeks of work, not partial weeks, so round up to the nearest whole week. Luc has been saving for at least 6 weeks. If Luc saved his wages of $75 a week for 6 weeks, he would have saved $450 plus the $50 from his grandparents, for a total of $500. The game system costs $450, so Luc would have $50 left after his purchase.

2. Warm up #2 • In 2008, about 66.1 million U.S. households had both landline phones and cell phones. At that time, it was expected that the number of households with both landline and cell phone service would decrease by an average of 5 million households per year. Approximately 27.8 million households had only cell phones, and it was expected that the number of households with only cell phones would increase by an average of 15 million households per year. According to this data, in about how many years would the number of households with only cell phone service be greater than the number of households with both cell phones and landlines? 15x + 27.8 > -5x + 66.1 20x> 38.3 w > 1.915 People with only cell phones will be greater in 2 years.