i) 40 – (22) = +40 – 22
= +(18 + 22)-22
= 18 +(22-22)
= 18 + 0
∴ 40-(22) = + 18
ii) 84 – (98) = 84 – 98
= + 84 – 84 – 14
= (84 – 84) – 14
= 0 – 14
∴ 84 – (98) = – 14
iii) (-16) + (-17) = -16 – 17 = – 33
∴ (-16) + (-17) = -33
iv) (-20) – (13) = – 20 – 13 = -33
∴ (-20) – (13) = – 33
v) 38 – (-6) = 38 + 6
We know – (-a) = a = + 44
∴ 38 – (-6) = + 44
vi) (-17) – (-36) = -17 + 36
We know – (- a) = a
= -17 + 17 + 19
= (-17+17) + 19
= + 19
∴ (-17) – (-36) = + 19