Good day...need ur help with this.. By trial and error, it is obvious that x=2. But how should we do this without using trial and error? That is, by any step by step method. If any. thanks

Printable View

- October 2nd 2013, 06:48 PMaldrincabrera3^(x-1) + 25^(3x/2) = 15628
Good day...need ur help with this.. By trial and error, it is obvious that x=2. But how should we do this without using trial and error? That is, by any step by step method. If any. thanks

- October 2nd 2013, 08:28 PMtopsquarkRe: 3^(x-1) + 25^(3x/2) = 15628
- October 2nd 2013, 09:10 PMvotanRe: 3^(x-1) + 25^(3x/2) = 15628
- October 2nd 2013, 09:24 PMtopsquarkRe: 3^(x-1) + 25^(3x/2) = 15628
- October 2nd 2013, 09:54 PMaldrincabreraRe: 3^(x-1) + 25^(3x/2) = 15628
Hehehe, its okay.. i just dont know how to do this without trial and error

- October 16th 2013, 05:04 AMaldrincabreraRe: 3^(x-1) + 25^(3x/2) = 15628
i still cant get this... please help

- October 16th 2013, 05:52 AMMINOANMANRe: 3^(x-1) + 25^(3x/2) = 15628
Aldrincambrera :

As Top squark mentioned above such kind of equations cannot be solved using algebraic methods...however:

transform the given equation into the form 3^x +3(125)^x =46884 then analyse the 46884 into the form 3^2+3(125)^2 and the solution x=2 is obvious.........

Have a good day.

In memory of my student Stefanos who died today ............may god bless his soul...........................

Minoas - October 16th 2013, 05:53 AMProve ItRe: 3^(x-1) + 25^(3x/2) = 15628
You've already been told that there is not a way known to solve this equation exactly other than trial and error. If there are any other solutions you'll need to get approximations for them using numerical methods.

- October 16th 2013, 08:14 AMWLXRe: 3^(x-1) + 25^(3x/2) = 15628
3^(x-1)+25^(3/2x)=15628

3^(x-1)+(25^3/2)x=5^6 + 3

3^(x-1)+5^3x =5^6 + 3

x-1 =1 3x=6

x =2 x=2