1. (√x)^3/4√x^3
A.x-2/3
B.x3/4
C.1/4x^3
D.x^3/2
2.Solve 8^2x+1+4^3x-1=33
A.1/6
B.1?3
C.0
D.29/28
3.Solve 125x^3/2-27=0 forx＞0
A.√3/5
B.√5/3
C.9/25
D.25/9
MC question
2010-12-09 12:55 am
回答 (1)
2010-12-09 1:25 am
✔ 最佳答案
1)(√x)^3/4√x^3= [(√x)^3] /4 √x^3= [x^(3/2)] /4 x^(3/2)= (x^3)/4(B)2)8^2x+1+4^3x-1=33(2^3)^(2x+1) + (2^2)^(3x-1) = 332^(6x+3) + 2^(6x-2) = 33[2^(6x-2)] (2^5 + 1) = 332^(6x-2) = 12^(6x-2) = 2^06x - 2 = 0x = 1/3(B)
3)125x^3/2-27=0 forx＞0125x^(3/2) - 27 = 0x^(3/2) = 27/125[x^(1/2)]^3 = (3/5)^3x^(1/2) = 3/5x = 9/25(C)
收錄日期: 2021-04-21 22:22:36
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20101208000051KK00636