Solving and Writing Two-Step Equations

You bought a magazine for $5 and four erasers. You spent a total of $25. How much did each eraser cost?  (Define 'n' and write the equation.) 

• n=total cost of erasers; 5 + 4n = 25

• n=cost of 1 eraser; 5 - 4n = 25

• n=cost of 1 eraser; 5n + 4 = 25

• n=cost of 1 eraser; 5 + 4n = 25

3f - 12 = -3

• 3

• -3

• 11

• 12

Which equation matches the following situation? 331 students went on a field trip. Six buses were filled and 7 students traveled in a car. How many students were in each bus?

• n= # of students in each bus; 6n + 7 =331

• n=# of buses; 6n + 7 =331

• n= # of students in each bus; 6 + 7n =331

• n= # of students in each bus; 6n - 7 =331

A taxi charges $3, plus $1.50 for each mile traveled. Mr. Maxwell rode in the taxi from his home to the airport and was charged $30. How many miles does Mr. Maxwell live from the airport? (Write an equation first and solve)

• 18 miles

• 20 miles

• 22 miles

Mathematical Equivalence

ON

Mathematical Equivalence

ON

3c + 5 = 23

• c = 3

• c = 6

• c = 7

• c = 18

What is the last step you should do to solve this equation?

• Add 6 to both sides

• Divide both sides by -6

• Divide both sides by 36

• Multiply both sides by -6

How would you solve each equation?

• divide both sides of = by 4

• x+4=12

• add 4 to both sides of =

• 4x=12

• subtract 4 from both sides of =

• multiply both sides of = by 4

• x-4=12

What is the first step you should do to solve this equation?

• Add 31 to both sides

• Subtract 31 from both sides

• Subtract 5 from both sides

• Divide by -6 on both sides