1. (a^-x) * (a^2x-1) = a^3
2. (3^x + 1) +( 3^x ) - 36=0
3. (5^x +1) - (5^x) - 100=0
4. (9^x) + (9^x-1) -10 = 0
4 S.3 Indices questions (10 points)
2008-10-07 1:20 am
回答 (1)
2008-10-07 1:45 am
✔ 最佳答案
1. (a-x) (a2x-1) = a3
a-x+2x-1 = a3
ax-1 = a3
x -1 = 3
x = 4
=====
2.
3x+1 + 3x - 36 =0
3(3x) + 3x = 36
3x(3 + 1) = 36
43x = 36
3x = 9
3x = 32
x = 2
=====
3.
5x+1 - 5x - 100 = 0
55x - 5x = 100
5x(5 - 1) = 100
5x4 = 100
5x = 25
5x = 52
x = 2
=====
4.
9x + 9x-1 - 10 = 0
99x-1 + 9x-1 = 10
9x-1(9 + 1) = 10
9x-110 = 10
9x-1 = 1
9x-1 = 90
x - 1 = 0
x = 1
=
收錄日期: 2021-04-23 23:05:30
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https://hk.answers.yahoo.com/question/index?qid=20081006000051KK01174