[問題]GWD 13-29

[winrewqnie]

which of the following is equal to (2^12 - 2^6)/(2^6 - 2^3)?
A. 2^6+2^3
B. 2^6-2^3
C. 2^9
D. 2^3
E. 2

我覺得我的腦袋打結了，我一直想把上面式子改成
(2^6*2^6-2^6)/(2^3*2^3-2^3)但又覺得怪怪的，請教一下。

[micki]

(2^12 - 2^6)= 2^6(2^6-1)=2^6(2^3-1)(2^3+1)
(2^6 - 2^3)=2^3(2^3-1)

thus
(2^12 - 2^6)/(2^6 - 2^3) = 2^3(2^3+1) = 2^6+2^3

我選 A

[winrewqnie]

謝謝