Applications of Equations

The cost C (in dollars) of making n watches is represented by

C =15n + 85.

How many watches are made when the cost is $385?

• 2 watches

• 20 watches

• 30 watches

• 300 watches

A machine prints 230 movie posters each hour.

Write an equation to find the number of hours it takes the machine to print 1265 posters.

• 230 + h = 1265

• 1265 – h = 230

• 230h = 1265

• 230 / h = 1265

A machine prints 230 movie posters each hour.

Solve an equation to find the number of hours it takes to print 1265 posters.

• 5.5 hours

• 10 hours

• 230 hours

• 1035 hours

Write an equation to represent the situation.

The sum of twice a number and 13 is 75.

• 2(x + 13) = 75

• 2x + 13 = 75

• 2x – 13 = 75

• 13(2 + x) = 75

Solve an equation to find the unknown number.

The sum of twice a number and 13 is 75.

• The number is 24.5.

• The number is 31.

• The number is 44.

• The number is 62.

You begin with $25 in a savings account and $50 in a checking account. Each week you deposit $5 into savings and $10 into checking.

Write an expression to represent the amount in your savings account after x weeks.

• 25 + x

• 25 – x

• 25 + 5x

• 25 – 5x

You begin with $25 in a savings account and $50 in a checking account. Each week you deposit $5 into savings and $10 into checking.

Write an expression to represent the amount in your checking account after x weeks.

• 25 + x

• 50 + x

• 25 + 5x

• 50 + 10x

You begin with $25 in a savings account and $50 in a checking account. Each week you deposit $5 into savings and $10 into checking.

After how many weeks is the amount in checking twice the amount in savings?

• After 1 week

• After 2 weeks

• The amount in checking is always twice the amount in savings

• The amount in checking will never be twice the amount in savings.

Using the diagram, write an expression to represent the route from your home to the store that passes the beach.

• 3x

• 3x + 3

• 3x + 4

• 4x + 4

Using the diagram, write an expression to represent the route from your home to the store that passes the park.

• 4x + 1

• 4x + 5

• 5x

• 5x + 2