Question 110166
This may help you.

-5+(-5) equals -10  if you are adding two negative numbers, add the numbers together and keep the negative sign.

If the problem looks like this 5+-3=? then you are adding a positive number to a negative number.  In this type of problem, you will take the difference of the two numbers and use the sign of the higher number (in this case it would be positive, because the positive 5 is greater than the -3)