Can someone explain to me how to add and subtract integers without using a number line? what's the rule for it?

ADD:
If both numbers are positive or negative then you have to add them if its a negative then your answer is a negative.6+1=7;-4+-1=-5

If one of the numbers are negative and the other one is positive then you will have to subtract.Then find the bigger number in the problem if its a negativie then your answer is a negative if your number is positive then your answer is a positive.-9+1=-8;4+-3=1

Sorry Don't Know What The Rules For Subtraction.But Hope This Helped You For Adding.

I'd say d, none of the others make sense.