Evaluate

👨🏻‍🏫 學術台數學

Lun

2007-06-12 10:20 am

Evaluate (2^-3X3^-2)^-1

回答 (2)

用戶4872

2007-06-12 6:00 pm

✔ 最佳答案

首先所有數負次方即係倒數..
eg x^-1 = 1/(x^1), x^-2 = 1/(x^2)

(2^ -3X3^ -2)^ -1
= 1/(2^ -3 * 3^ -2)
= 1/(1/2^3 * 1/3^2)
= 1/(1/8* 1/9)
= 1/(1/72)
= 72

參考: me

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winniechow_11

2007-06-12 9:05 pm

不用那麼複雜的
(2^-3X3^-2)^-1
=2^-3(-1) x 3^-2(-1) [先解括號,,將-1乘落去-3 同-2]
=2^3 x 3^2 [由於負負得正,,-3(-1)同-2(-1) 變成3同2]
=8 x 9 [2的3次方==8 ,,, 3的2次方==9}
=72

參考: myself

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