positive 7 plus negative 8

Thanks SoulReaper, that is a good answer   

Anon, If you are serious about understanding, this post might help.

you can try answering the questions too if you want to.   After you finish I can give you the answers.

http://web2.0calc.com/questions/positive-and-negative-numbers-directed-numbers

1) Now -3+8 Start at -3 and go 8 in the positive direction and what do you get? 
2) Now 4 - 9 start at 4 and go 9 in the negative direction and what do you get? 
3) Now -2- 8 start at -2 and go 8 in the negative direction and what do you get? 
4) 0-8= 
5) -2-+6= 
6) 1-4+(-7)= 
7) -9++4 = 
8) 13+(-5)= 
9) -4 x 6 = 
10) 3 x -6 = 
11) -5 x -3= 
12) 20 / -4= 
13) -8 / 2= 
14) -15 / -5= 
15) +4 x +7=

+7-8= -1

-7+8= 1

-7-8= -15

-7+8 = 1

Always remember that

2 negatives (minus negative something) is positive

2 positives (plus positive something) is positive

1 negative and 1 positive is negative

Good Luck :)