\(a)\, 18.17 – 3.6.7\) \( = 18.17 – 18.7\) \( = 18.(17 – 7) \) \(= 18.10 = 180\)
\(b) \,54 – 6.(17 + 9) = 54 – 102 – 54 \)\(= (54 – 54) – 102 = -102\)
\(c) 33.(17 – 5) – 17.(33 – 5)\) \( = 33.17 – 33.5 – 17.33 – 17.5\) \(= (33.17 – 33.17) – 5(33 – 17)\) \( = 0 – 5.16 = - 80\)
