Answer:
<em>Addition Property of Equality</em>
Step-by-step explanation:
<u>System of Equations</u>
When two equations are given and two variables are unknown in both equations, then we can solve the system in several ways.
One method consists in adding both equations term by term and eliminate one of the variables. That property is called the addition of equalities. Let's consider the equations given in the problem:
If we add both equations, we have
Simplifying
By adding both equations we managed to eliminate the variable y and could easily find the value of x
Answer: Addition Property of Equality