6條關於indices&surds+1條equation

Orzzzz

2009-07-20 9:46 pm

除左第1-6題之外, 第29題要詳細咁回答, 當然最好第1-6題都有解釋下-3-!! 唔該哂 ; )

問題睇下圖:
http://i780.photobucket.com/albums/yy85/614shirley/ASK.png

多數唔會死圖掛(?)=_=v

回答 (1)

用戶9112

2009-07-20 11:32 pm

✔ 最佳答案

(1)a.a(a+a)
=a.a.2a
=2a3 (B)
(2)2x8y
=2x(23)y
=2x23y
=2x+3y (A)
(3)3x9y
=3x(32)y
=3x32y
=3x+2y (A)
(4)22n9n/3n
=(22)n9n/3n
=(4.9/3)n
=12n (C)
(5)81x=272y
(34)x=(33)2y
34x=36y
4x=6y
x/y=6/4=3/2
x:y = 3:2 (D)
(6)(an-2+an-1)/an-2
=(an-2+a1+n-2)/an-2
=(an-2+a.an-2)/an-2
=an-2(1+a)/an-2
=1+a (E)
(29)One part x, the other part is 36-x
Let side of square = s
Perimeter = 4s = x
So s = x/4
Let radius of circle = r
Circumference of circle = 2πr = 36-x
So r = (36-x)/ 2π
Side of square = radius therefore x/4 = (36-x)/ 2π

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