Lesson Vocabulary 

Equivalent Equations 
Equations that have the same solutions. 
Addition Property of Equality 
Adding the same number to both sides of the equation doesn't change the equation. 
Subtraction Property of Equality 
Subtracting the same number from both sides of the equation doesn't change the equation. 
Isolate 
Means to get a variable all alone by itself. You do this using the other properties mentioned in this section. Once you have the variable all alone by itself, you have the answer to the algebra problem. 
Inverse Operations 
Inverse operations "undo" other operations. For example, subtraction undoes addition; multiplication undoes division; and so on. Every mathematical operation has an inverse operation. 
Multiplication Property of Equality

Multiplying both sides of the equation by the same number doesn't change the equation. 
Division Property of Equality 
Dividing both sides of the equation by the same number doesn't change the equation. 