【o9770221】評論
（5.17×104）＋（4.3×103）= 51.7 × 103 + 4.3 × 103 = (51.7 + 4.3) × 103 = 56 × 103 = 5.6 × 104
【o9770221】評論
（5.17×104）＋（4.3×103）= 51.7 × 103 + 4.3 × 103 = (51.7 + 4.3) × 103 = 56 × 103 = 5.6 × 104
【cy940756】評論
（5.17×104）＋（4.3×103）=51.7x103+4.3x103=(51.7+4.3)x103=56x103=5.6x104答案選項d