1. (3 + 2√5)(3 - 3√5)
2. (5 + 2√7)(1 - 2√7)
3. (3√11 - 4)(4 + 3√11)
3題超易化簡題...急
2009-09-06 4:14 am
回答 (1)
2009-09-06 4:49 am
✔ 最佳答案
1. (3 + 2√5)(3 - 3√5)
= 3(3 - 3√5) + 2√5(3 - 3√5)
= 9 - 9√5 + 6√5 - 30
= -21 -3√5
2.
(5 + 2√7)(1 - 2√7)
= 5(1 - 2√7) + 2√7(1 - 2√7)
= 5 - 10√7 + 2√7 - 28
= -23 - 8√7
3.
(3√11 - 4)(4 + 3√11)
= 3√11(4 + 3√11) - 4(4 + 3√11)
= 12√11 + 99 - 16 - 12√11
= 83
收錄日期: 2021-04-13 16:49:56
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