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