Tính nhanh: 10000 – 47 × 72 – 47 × 28.

10000 ‒ 47 × 72 ‒ 47 × 28

= 10000 ‒ 47 × (72 + 28)

= 100 × 100 ‒ 47 × 100

= 100 × (100 ‒ 47)

= 100 × 53

= 5300.