Models One Step Equations for Adding and Subtracting

In the equation
x + 7 = 12
7 is being added to the variable, x. How should you show your work to isolate the variable and solve the equation? 

• Subtract 7 from both sides. The solution is x = 5.

• Add 7 to both sides.
  The solution is x = 19.

• Multiply both sides by 7 The solution is x = 84.

5 less than a number is 15.

• x - 5 = 15

• 5 - x = 15

• 15 - x = 5

Which choice models this situation? Marcus needs to sell 25 tickets to a fundraiser by Friday. So far, he has sold 9 tickets. How many tickets does he still need to sell?

• t - 9 = 25

• t + 9 = 25

• 9t = 25

• t/9 = 25

Solve the equation.

x + 9 = -5

Mathematical Equivalence

OFF

Write the equation for the model. (white square=1 rectangle=x red square = -1)

• 7=x+3

• 7=x+(-3)

• 7=-x+3

• -7=x-3

Write the equation for the model.

• 7=x+3

• 7=x+(-3)

• 7=-x+3

• -7=x-3

Solve the following equation 
8 = m - 12

• 4

• 0.5

• 5.0

• 20

-16+ x= -15

• 2

• 0

• -1

• 1

What equation matches this situation?
Robyn had some video games then bought 4 more.  Now she has a total of 10 games.

• v - 4 = 10

• v + 4 = 10

• 10 - 4 = v

• Answer not Given

Solve the following equation
1 + a = 15

• 14

• 16

• 12

• - 16