SOLUTION: I have to solve this problem by the addition method. I do have a book but this problem is not out of a book,it's from a handout. I tried to follow the steps in the book to do this

You can put this solution on YOUR website!
Edit: does not always equal , but always. That is what we are doing when we take Equation 1 minus Equation 2. To illustrate my point, I will show it step-by-step:

Simplify the on the right side of the =.

Remove unnecessary brackets (or parentheses, depending on what you want to call them).

Now we remove the other pair of brackets. However, the sign before the open bracket is a minus sign, so we change the + sign inside the bracket to a -.

To understand why we must change the sign, consider this example. Let x be apples and y be oranges. When I perform , I am taking away 1 apple and 4 oranges. That would have the same effect as taking away 1 apple, , and then taking away 4 oranges, , so:

We have .
Rearranging the terms,

Simplifying x,

Obviously +4y and -4y cancel each other out, so our final equation is


---
We are given two equations:
Equation 1:
Equation 2:
Subtracting Equation 2 from Equation 1, we obtain:



Then, substitute into Equation 2:



Since and , the solutions of (,) are (,), and the answer is .