Functions Review Part B

Ben currently has $70 in his trip fund. He makes $45 per week doing yard work for his neighbors. He keeps $18 of the $45 for weekly expenses. The remaining amount goes into his trip fund.

Which function can be used to determine the amount of money (y), in dollars, that Ben has in his trip fund at the end of x weeks?

• y = 70 + 27x

• y = 52 + 45x

• y = 45 + 52x

• y = 27 + 70x

Zach is studying the school furnace’s oil usage. He records the amount of oil remaining in the tank at 8 a.m. every day for a week. No additional oil is added to the tank during the week. The graph shows his data.

As the outdoor temperature gets colder, more oil is used to keep the indoor temperature constant. Based on the graph, which 24-hour time interval indicates the coldest period for the week?

• Sunday to Monday

• Tuesday to Wednesday

• Friday to Saturday

• Saturday to Sunday

The total cost to rent a bicycle includes a fixed fee to rent a helmet and an hourly fee. Lou can rent a bicycle for 4 hours for $55.00 or 6 hours for $80.00.

Which equation can be used to find y, the total cost to rent a bicycle for x hours?

• y = 12.5x

• y = 12.5x + 5

• y = 25x

• y = 25x + 5

A student goes on a 20-mile bicycle ride. The graph shown below represents the distance (y), in miles, the student has traveled based on the time (x), in minutes, since beginning the bicycle ride.

During which time interval did the student travel at the fastest rate?

• 0 minutes to 30 minutes

• 30 minutes to 40 minutes

• 40 minutes to 70 minutes

• 70 minutes to 80 minutes

Daisy has a bus pass with a balance of $30 on it. She uses the bus pass to pay for bus fares. The price for each bus fare is $1.50.

Which equation represents the bus pass balance (y), in dollars, based on the number of bus fares, x, she pays for?

• y = 1.5x + 30

• y = -1.5x – 30

• y = -1.5x + 30

• y = 1.5x – 30

A tank had 90 gallons of water in it. The tank is drained at a rate of 5 gallons per minute.

Which graph represents the number of gallons of water, y, in the tank x minutes after it begins to drain?

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Marcie drives from Swan Valley to Eagle Grove. She drives at a constant rate and then stops for lunch. After lunch, she drives at the same rate she drove before lunch until she reaches Eagle Grove.

Which graph could be used to represent Marcie’s drive?

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Sonia opened a savings account and then added the same amount to the savings account every week. After 5 weeks, her savings account had a total of $45. After 10 weeks, her savings account had a total of $70.

Which equation represents the amount of money (y), in dollars, in Sonia’s savings account after x weeks?

• y = 7x

• y = 9x

• y = 5x + 20

• y = 20x + 5

The manager of a small chain of restaurants compared the sales at different restaurant locations. She drew a graph comparing the daily sales, in dollars, to the number of competing restaurants in the neighborhood.

Based on the graph, how much do the daily sales change with each additional competitor in the neighborhood?

• The daily sales increase by $100.

• The daily sales decrease by $100.

• The daily sales increase by $200.

• The daily sales decrease by $200.

Luis is building a new deck and needs to have a slab of concrete poured. He knows the contractor charges an initial cost of $75 plus an additional $2.50 per square foot of concrete.

Which equation can be used to determine the cost (y), in dollars, to pour a concrete slab with an area of x square feet?

• y = 2.5x + 75

• y = 7.5x + 2.5

• y = 75x + 2.5

•  y = 77.5x