6) Solve for x: (1/5)^x = 5^x+6?
回答 (3)
2016-05-31 8:59 am
(1/5)^x = 5^(x + 6)
[(5^(-1))^x = 5^(x + 6)
5^(-x) = 5(x + 6)
-x = x + 6
-2x = 6
x = -3
[(5^(-1))^x = 5^(x + 6)
5^(-x) = 5(x + 6)
-x = x + 6
-2x = 6
x = -3
2016-05-31 11:33 am
It can't be solved analytically, but if you meant (1/5)^x = 5^(x + 6), then
(1/5)^x = 5^(x + 6)
5^-x = 5^(x + 6)
-x = x + 6
-2x = 6
x = -3
(1/5)^x = 5^(x + 6)
5^-x = 5^(x + 6)
-x = x + 6
-2x = 6
x = -3
2016-05-31 9:11 am
Presentation troubles me !!!
I have a funny feeling that should be shown as :-
(1/5)^x = 5^(x + 6)
x log (1/5) = (x + 6) log 5
- 6 log 5 = [ log 5 - log(1/5) ] x
- 6 log 5 = [ log 25 ] x
- 6 log 5 = [ 2 log 5 ] x
- 6 = 2 x
x = - 3
I have a funny feeling that should be shown as :-
(1/5)^x = 5^(x + 6)
x log (1/5) = (x + 6) log 5
- 6 log 5 = [ log 5 - log(1/5) ] x
- 6 log 5 = [ log 25 ] x
- 6 log 5 = [ 2 log 5 ] x
- 6 = 2 x
x = - 3
收錄日期: 2021-04-18 14:55:58
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