There is an inverse relationship between addition and subtraction.

Example: Since 3 + 7 = 10 then the following are also true:

Similar relationships exist for subtraction.

Example: Since 10 - 3 = 7 then the following are also true:

An equation is balanced or the same on either side of the equals (=) sign. If exactly the
same thing is done to both sides of the equation, it will still be balanced or equal.

In the example above we start with the equation 3 + 7 = 10:

- Subtract the same number from both sides

3 + 7 - 3 = 10 - 3
- On the left side the 3 and -3 produce 0 which leaves

7 = 10 - 3
- Turning the equation around to be in more normal form

10 - 3 = 7