In integer, when we have the same numbers and different sign then what we can do [+/-]?

Rules of integers for addition and subtraction

1) If the two numbers have a different sign like positive and negative then subtract the two numbers and give the sign of the bigger number.

Eg: $17 - 8 = + 9;   -12 + 5 = -7$ 

2) If the two numbers have the same sign i.e. either positive or negative signs then add the two numbers and give the common sign.

Eg:  $6 + 9 = 15;  -8 - 7 = -15$

Integer Multiplication

$ +  x  + = +     Eg:  +2  x  +3 = +6$ 

$+ x - = -         Eg:  +2  x  - 3 = - 6$ 

$- x + = -        Eg:  - 2  x  +3 = - 6$ 

$- x - = +        Eg:  -2  x  -3 = +6$ 

Integer Division

$ +  /  + = +     Eg:  +6  /  +3 = +2 $

$+ / - = -         Eg:  +6  /  - 3 = - 2$ 

$- / + = -        Eg:  - 6  /  +3 = - 2$ 

$- / - = +        Eg:  -6  x  -3 = + 2$