花10元買份報紙 中了千萬元

利用分配律算下列各題

1. (-4)×(-987)-(-6)×13

2. 31×17-31×7-11×17+11×7

3.15×16-15×44-5×16+5×44?





利用分配律算下列各1.(-4)×(-987)-(-6)×132.31×17-31×7-11×17+11×73.15×16-15×44-5×16+5×44更新:急



1. (-4) × (-987) - (-6) × 13 = (-4) × (13 - 1000) - (-6) × 13 = (-4) × 13 - (-4) × 1000 - (-6) × 13 = (-4) × 13 - (-6) × 13 - (-4) × 1000 = [(-4) - (-6)] × 13 - (-4) × 1000 = (-4 + 6) × 13 + 4 × 1000 = 2 × 13 + 4 × 1000 = 26 + 4000 = 4026 2. 31 × 17 - 31 × 7 - 11 × 17 + 11 × 7 = 31 × 17 - 11 × 17 + 11 × 7 - 31 × 7 = (31 - 11) × 17 + (11 - 31) × 7 = 20 × 17 + (-20) × 7 = 20 × 17 - 20 × 7 = 20 × (17 - 7) = 20 × 10 = 200 3. 15 × 16 - 15 × 44 - 5 × 16 + 5 × 44 = 15 × 16 - 5 × 16 + 5 × 44 - 15 × 44 = (15 - 5) × 16 + (5 - 15) × 44 = 10 × 16 + (-10) × 44 = 10 × 16 - 10 × 44 = 10 × (16 - 44) = 10 × (-28) = -280



1.(-4)×(-987)-(-6)×13=40262.31×17-31×7-11×17+11×7=2003.15×16-15×44-5×16+5×44=-280

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