Tính nhanh a) 576 + 678 + 780 – 476 – 578 – 680
Giải thích
a) 576 + 678 + 780 – 476 – 578 – 680 = (576 – 476) + (678 – 578) + (780 – 680) = 100 + 100 + 100 = 100 × 3 = 300 | b) (126 + 32) × (18 – 16 – 2) = (126 + 32) × 0 = 0 |
a) 576 + 678 + 780 – 476 – 578 – 680 = (576 – 476) + (678 – 578) + (780 – 680) = 100 + 100 + 100 = 100 × 3 = 300 | b) (126 + 32) × (18 – 16 – 2) = (126 + 32) × 0 = 0 |