solve the following exponential equations
1. 4^x - 3 = 10/4^x
2. 2^x2-4 = 8^x
3. (5^x)^2 - 7(5^x) + 6 = 0
4. 4^x - 5(2^x) + 4 = 0
5. 3^5-x = 36-3^x
F4 Exp Eq
2012-05-26 6:48 pm
回答 (2)
2012-05-26 7:24 pm
✔ 最佳答案
1) 4x - 3 = 10/4x(4x)2 - 3(4x) - 10 = 0
(4x - 5) (4x + 2) = 0
4x = 5 or -2 (rej)
x = log 5/log 4
2) 2x^2-4 = 8x
2x^2-4 = 23x
x2 - 4 = 3x
x2 - 3x - 4 = 0
(x - 4)(x + 1) = 0
x = 4 or -1
3) (5x)2 - 7(5x) + 6 = 0
(5x - 6)(5x - 1) = 0
5x = 6 or 1
x = log 6/log 5 or 0
4) 4x - 5(2x) + 4 = 0
(2x)2 - 5(2x) + 4 = 0
(2x - 4)(2x - 1) = 0
2x = 4 or 1
x = 2 or 0
5) 35-x = 36 - 3x
243/3x = 36 - 3x
243 = 36(3x) - (3x)2
(3x)2 - 36(3x) + 243 = 0
(3x - 27)(3x - 9) = 0
3x = 27 or 9
x = 3 or 2
參考: 原創答案
2012-05-27 2:03 am
001 is doing well.
收錄日期: 2021-04-25 23:01:42
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20120526000051KK00113