straiders Posted October 25, 2012 Report Share Posted October 25, 2012 Hola!" Bueno tengo un par de ejercicios que no he podido resolver, asi que recurro en su ayuda. Acá van:1) 3^x por 5^2x=4 2) 25^x+5^x=20 3) 3^2x- 4 por 3^(x+1) DE ANTEMANO GRACIAS Link to comment Share on other sites More sharing options...
cañangasñangas Posted October 25, 2012 Report Share Posted October 25, 2012 (edited) te doy el primero Edited October 27, 2012 by cañangasñangas Link to comment Share on other sites More sharing options...
ingmarov Posted October 26, 2012 Report Share Posted October 26, 2012 (edited) el segundo: CORREGIDO(25x) + (5x) = 20=(5x)(5x) + (5x) = 20=52x + 5x = 20 implica que: 52x + 5x - 20 = 0sustituyendo 5x = u nos quedau2 + u - 20 = 0= (u+ 5)(u - 4) = 0y esto es verdad si u = -5 ó u = 4 como u = 5xtenemos que:5x= -5 no hay solución real para esta ecuacion.pero para 5x = 4 x = log(4)/log(5) x = 0,861353116 (aproximadamente) Edited November 2, 2012 by ingmarov Link to comment Share on other sites More sharing options...
cañangasñangas Posted October 26, 2012 Report Share Posted October 26, 2012 el tercero y suponiendo que es [3^(2x-4)][3^(x+1)]: Link to comment Share on other sites More sharing options...
TheTruth Posted October 31, 2012 Report Share Posted October 31, 2012 el segundo:(25x)(5x)=(25*5)x=125x=20 entonces x=log 20/log 125 otra forma(25x)(5x)=(52)x(5x)=(52x)(5x)=53x=20 entonces x=log 20/3log 5 x=0.620451039 (valor aproximado) pero no es una multiplicación, es una suma Link to comment Share on other sites More sharing options...
ingmarov Posted November 2, 2012 Report Share Posted November 2, 2012 el segundo:(25x)(5x)=(25*5)x=125x=20 entonces x=log 20/log 125 otra forma(25x)(5x)=(52)x(5x)=(52x)(5x)=53x=20 entonces x=log 20/3log 5 x=0.620451039 (valor aproximado) pero no es una multiplicación, es una suma Pero que error mas infantil, lo siento mucho, corrijo mi error aunque ahora es demasiado tarde. Link to comment Share on other sites More sharing options...
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