Biểu diễn các hiệu sau thành tổng rồi tính: a) (–23) – 12 b) 43 – (–53) c) (–15) – (–17) d) 14 – 20

a)

(–23) – 12 = (–23) + (–12) = –35

b)

43 – (–53) = 43 + 53 = 96

c)

(–15) – (–17) = (–15) + 17 = 2

d)

14 – 20 = 14 + (–20) = –6.