a+b+c−(a−b−c)=?
Firstly we need to look at the expression inside of parentheses.
Remember:
When we multiply a negative number by a negative number, the result will be positive.
When we multiply a positive number by a negative number, the result will be negative.
Therefore:
Now let's combine the terms:
Then we can combine the terms:
Finally let's combine the terms:
This leaves us with: