Solving Equations for Variables

Solve for b
2b = -16

• 8

• 4

• -8

• 3

x = 20

x = 7

x = 10

x = 3

• x = 20

• x = 7

• x = 10

• x = 3

r + 20 = 27

• r = 7

• r = 47

• r = 13

• r = 20

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.

Solve the equation:
-5x = 25

• x = 20

• x = -20

• x = -5

• x = 5

What is the result of solving for the variable?

-2x = 6

• x = -12

• x = 3

• x = -3

• x = 12

Kylie and Ricardo decide to start a dog watching business for their neighborhood. Kylie thinks it would be best to charge customers $27 for a membership and then $5 per time they walk a dog. Ricardo thinks it would be best to charge $8 per dog walk. For what number of walks will their two plans cost the same amount of money?

Mathematical Equivalence

ON

Find the solution:
10 = 4x - 2

• x = 3

• x = 2

• x = -3

• x = -2

Solve:

3(x - 2) = 18

• 6.7

• 4

• 8

• -4

• none of the above

1. Kylie and Ricardo decide to start a dog watching business for their neighborhood. 

3. Kylie thinks it would be best to charge customers $27 for a membership and then $5 per time they walk a dog. 

5. Ricardo thinks it would be best to charge $8 per dog walk. 

7. For what number of walks will their two plans cost the same amount of money?

Mathematical Equivalence

ON