What is to be added to 5, to get −3?
The number to be added to 5 to get −3 is obtained by subtracting 5 from −3.
−3 − 5 = −8
So, −8 should be added to 5 to get −3.
What should be added to - 1 to get −35 ?
What should be added to (12+13+15) to get 3?