Equation Models and Word Problems

Grace uses the equations y = 25x + 20 to calculate the dollar amount, y, she earns from renting out a lawnmower x times.  She want to solve for x in order to find the number of times she needs to rent a lawnmower to earn a given amount.  Which equation should she use?

• x = (y/25) - (4/5)
• x = (y/25) - 20
• x = (y + 76)/25
• x = (y + 20)/25

Tags

CCSS.HSA.CED.A.4

The formula to convert degrees Fahrenheit to degrees Celsius is C = (5/9)(F-32). Which formula can be used to convert degrees Celsius to degrees Fahrenheit?

• F = (5/9)C + 32
• F = (9/5)C - 32
• F = (9/5)C + 32
• F = (9/5)(C+32)

Tags

CCSS.HSA.CED.A.4

A plumber charges a fixed rate of $40 per job plus $10 for each hour, h, that he works at the job.  Which equation models the total amount the plumber charges, y, if he works h hours?

• y  = 30h
• y = 50h
• y = 10h + 40
• y = 40h + 10

Tags

CCSS.8.F.B.4

CCSS.HSF.LE.A.2

A rectangle has a perimeter of 144 inches.  The width of the rectangle is 12 inches less than the length.  What is the width of the rectangle?

• 27
• 30
• 39
• 42

The formula V = (1/3)Bh can be used to find the volume of a cone that has a base area B and height h.  Which formula expresses the height of the cone in terms of volume and base area?

• h = V/(3B)
• h = 3V - B
• h = (3V)/B
• h = B/(3V)

Tags

CCSS.HSA.CED.A.4

Which expression represents the value of x in the equations ax+b=c.

• (c-b)/a
• (b+c)/a
• a/(c-b)
• a/(b+c)

Tags

CCSS.HSA.REI.B.3

The perimeter of a rectangle can be found using the formula P=2L+2W, where L is the length and W is the width.  Which formula represents the length of a rectangle in terms of the perimeter and width?

• L = P - (2W)/2
• L = (P-2W)/2
• L = (1/2)P - 2W
• L = (1/2)P - (1/2)W

Tags

CCSS.HSA.CED.A.4

An electrician charges $42 per hour. He estimates that he will need $628 in materials for a project and the total cost of the project will be $1,384.  How many hours does the electrician expect the job to take?

• 18 hours
• 33 hours
• 42 hours
• 48 hours

Tags

CCSS.7.EE.B.4A

The formula W=fd can be used to calculate the amount of work it takes to move a force, f, a specific distance, d.  Which formula can be used to calculate distance, d?

• d = W -f
• d = W + f
• d = Wf
• d = W/f

Tags

CCSS.HSA.CED.A.4

Solve the equation for y: 4x - 5y = 20

• y = -4 + 4x

• y = -4 + (4x/5)

• y = 4 - (4x/5)

• y = 4 + 4x

Tags

CCSS.6.EE.C.9