Modeling Linear Inequalities

The function f(x) = 800x +4000 represents Carlos's total sales as a function of the number of laptop computers he sells. How many computer must he sell to earn exactly $8000?

• 7

• 5

• 6.5

• 4

The function f(x) = 800x +4000 represents Carlos's total sales as a function of the number of laptop computers he sells. How many computer must he sell to earn more than $12500?

• 10

• 11

• 10.6

• 9

The function f(x) = 13x + 52 represents the total number of points Leon will score this season. Write and inequality for when how games until Leon scores 85 or fewer points.

• $13x+52\ >85$

• $13x+52<85$

• $13x+52\ge85$

• $13x+52\le85$

The function f(x) = 13x + 52 represents the total number of points Leon will score this season. Determine how many games it will take for Leon to score at least 100 points.

• 3.7 games

• 3 games

• 4 games

• 11.7 games

A bathtub filled with 55 gallons of water is drained. The water drains at a rate of 5 gallons per minute. The function f(x) = -5x + 55 represents the volume of water in the tub as it drains. How many minutes have passed if the tub still has more than 20 gallons of water remaining in it?

• 7 minutes

• 15 minutes

• 12 minutes

• 5 minutes

A bathtub filled with 55 gallons of water is drained. The water drains at a rate of 5 gallons per minute. The function f(x) = -5x + 55 represents the volume of water in the tub as it drains. Write and inequality for when the tub has less than 10 gallons left.

• $-5x+55>10$

• $-5x+55\ge10$

• $-5x+55<10$

• $-5x+55\le10$

Joan needed $100 to buy a graphing calculator for her math class. Her neighbor will pay her $5 per hour to babysit and her Father gave her $10 for mowing the lawn. Which inequality represents the minimum amount of hours she will need to babysit in order for her to buy her calculator? (Hint 5x)

• 5x + 10 ≥ 100

• 5x - 100 ≥ 10

• 10x + 5 ≤ 100

• 5x + 10 > 100

The dance committee hired a DJ for the fall dance. The DJ charges $125 per hour in addition to $55 for an assistant. The committee wants to keep the total cost under $600. Which inequality represents the maximum amount of hours the DJ will play at the dance?

• 125x + 55 ≤ 600

• 125x + 55 ≥ 600

• 125x + 55 > 600

• 125x + 55 < 600

 Which inequality could be used to represent the situation: Mrs. Bailey graded more than 5 papers with no name on them. 

• x < 5
• x > 5
• x ≤  5
• x ≥ 5

 Which inequality could be used to represent the situation: At least 5 students wore jeans on jeans day.

• x < 5
• x > 5
• x ≤  5
• x ≥ 5