While adding or subtracting integers, we follow three rules
(1) + & − becomes −
2 + (−3) = 2 − 3
−4 − (+8) = −4 − 8
(2) + & + becomes +
5 + (+1) = 5 + 1
−7 + (+3) = −7 + 3
(3) − & − becomes +
4 − (−6) = 4 + 6
− 9 − (−2) = −9 + 2
Let’s look at some example
(1) 2 + (−3)
= 2 − 3
Taking − common
= −(−2 + 3)
= −(3 − 2)
= −1
(2) −4 − (+8)
= −4 − 8
Taking − common
= −(4 + 8)
= −12
(3) 5 + (+1)
= 5 + 1
= 6
(4) −7 + (+3)
= −7 + 3
Taking − common
= −(7 − 3)
= − 4
(5) 4 − (−6)
= 4 + 6
= 10
(6) −9 − (−2)
= −9 + 2
Taking − common
= −(9 − 2)
= −7