c) Tính: 28 × (7 – 2) (14 – 7) × 6
c) Tính:
28 × (7 – 2) (14 – 7) × 6
c) Tính:
28 × (7 – 2) = 28 × 7 – 28 × 2 = 196 – 56 = 140
(14 – 7) × 6 = 14 × 6 – 7 × 6 = 84 – 42 = 42