Tính: (3/5 - 3/20) × 4/5

= (12/20 - 3/20) × 4/5

= 9/20 × 4/5

= 9/25

36/100/=9/25

(3/5 - 3/20) × 4/5

= (12/20 - 3/20) × 4/5

= 9/20 × 4/5

= 36/100

= 9/25

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