Answer:
The negative sign is put before numbers to make them negative, or make their signs the opposite of what the are.
You have a 20.
+ 20
You don't need to put the + there if there is nothing before it, but that is a positive 20.
If you put a negative in front of it;
- (+ 20) = - 20
If you have a negative in front of parenthesis;
50 - (2x - 20)
50 - 2x + 20
70 - 2x
