Expressions Practice

David is driving to a concert and needs to pay for parking. There is an automatic fee of $9 just to enter the parking lot, and when he leaves the lot, he will have to pay an additional $3 for every hour he had his car in the lot. How much would David have to pay if he left his car in the lot for t hours?

• 3t + 9

• 3 + 9t

• 12t

• 3 + 9

Liam finds some nickels and pennies in his change purse. How many coins does he have if he has n nickels and p pennies?

• 5n + 10p

• n + p

• np

• 15np

A group leader writes the expression 10a + 8c to calculate the cost (in dollars) of taking a group of a adults and c children to the museum.

What is the cost for each adult?

• 8

• 10

• 18

• 10a

A group leader writes the expression 10a + 8c to calculate the cost (in dollars) of taking a group of a adults and c children to the museum.

She does the calculation 10(4) + 8(12) = 136.

What does this mean in this context?

• For 10 adults and 8 children the total cost is $136

• There are a total of 136 people in the group.

• The tickets cost $4 for each adult and $12 for each child.

• For 4 adults and 12 children, the total cost is $136

A biologist models the height (in cm) of a plant d days after transplating with the expression

10 + 1.2d

What was the plant's starting height?

• 1.2 cm

• 0 cm

• 10 cm

• 11.2 cm

A biologist models the height (in cm) of a plant d days after transplating with the expression

10 + 1.2d

Evaluate the expression for d = 10 and explain the result.

• 10 days after transplanting the plant's height is 22 cm

• The plant grows 22 cm every 10 days.

• 10 plants are a total of 22 cm tall

• The cost for growing 10 plants is $22

A catering company charges $50 up front plus $12 per person to cater a lunch. They use the expression 50 + 12x to determine the total charge.

Which best explains what the variable x represents?

• cost per person

• total charge

• number of days lunch is provided

• number of people