One Variable Equations Addition and Subtraction

10x = 90

• x = 80

• x = 100

• x = 10

• x = 9

What is the correct step to solve for the variable?
15 = m - 5

• add 15 to both sides

• add 5 to both sides

• subtract 15 from both sides

• subtract 5 from both sides

What are the two basic rules for solving algebraic equations?

• Whatever you do to one side of the equal sign, you must copy and do on the other side of the equal sign

• Negative signs can be ignored

• Always start on the left side, regardless of where the variable is

• Always do the opposite operation

To check your solution. You do what first?

• Isolate the variable

• Opposite

• Substitute the variable with the answer

• Use the "Golden Rule"

Solve the equation for the missing variable:

r + 20 = 27

• r = 7

• r = 13

• r = 47

• 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

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

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

• Subtract 12 from both sides. The solution is x = 9

Solve the equation for the missing variable:

s - 22 = 50

• s = 28

• s = 72

• s = 20

• s = 75

Solve the equation for the missing variable:

g - 15 = 30

• g = 35

• g = 15

• g = 45

• g = 12

Solve the equation for the missing variable:

s + 18 = 24

• s = 42

• s = 18

• s = 9

• s = 6

Solve the equation for the missing variable:

y - 33 = 147

• y = 114

• y = 180

• y = 177

• Answer not given