Question

How do you solve equations that contain addition or subtraction?

Answer 1

To learn the basics I would suggest using this simple model to solve. Remember, that you can add, subtract, multiply, or divide anything to both side of the equal sign.
Ex. 5 + 5 = x
-5 -5

Now, let's try a real problem:

10 + x = 15
Now, I know this may seem to be an easy problem, but by using the method I am about to show you, you will be able to solve any addition, subtraction, even multiplication, and division equation!
This would be how you solve:
10 + x = 15
-10 -10
----------------------------------------
x = 5

Hope this helped!

Answer 2

Any equation given, with a variable, could be solved by applying the inverse operation.

Example:-

4 + x = 8
-4 -4

x = 8 -4
x = 4

Answer; x = 4