• Asignatura: Matemáticas
  • Autor: mayralopez2018
  • hace 9 años

Ayuda porfa. Es pará un exámen

Adjuntos:

Respuestas

Respuesta dada por: helgapastelito
0
2)
 log(x + 1)  =  log(x - 1)  + 3 \\  log(x + 1)  =  log(x - 1)  +  log( {10}^{3} )  \\  log(x + 1)  =  log(1000(x - 1))  \\ x + 1 = 1000(x - 1) \\ x + 1 = 1000x - 1000 \\ 1 + 1000 = 1000x - x \\ 1001 = 999x \\ x =  \frac{1001}{999}
3)
2 log(x)  -  log(x + 6)  = 0 \\  log( \frac{ {x}^{2} }{x + 6}  )  =  log(1)  \\  \frac{ {x}^{2} }{x + 6}  = 1 \\  {x}^{2}  = x + 6 \\  {x}^{2}  - x - 6 = 0 \\ (x - 3)(x + 2)
Sol 1: x=3
Sol2: x=-2
Pero como x>0
La solucion es x =3

4)
 log(x + 1)   -  log(x)  = 1 \\  log( \frac{x + 1}{x} )  =  log(10)  \\  \frac{x + 1}{x}  = 10 \\ x + 1 = 10x \\ x - 10x =  - 1 \\  - 9x =  - 1 \\ x =  \frac{1}{9}
5)
 log(4x - 1)  -  log(x - 2)  =  log(5)  \\  log(  \frac{4x - 1}{x - 2}  )  =  log(5)  \\  \frac{4x - 1}{x - 2}  = 5 \\ 4x - 1 = 5(x - 2) \\ 4x - 1 = 5x - 10 \\  - 1 + 10 = 5x - 4x \\ 9 = x
6)
 log_{3}(x)  = 4 \\  {3}^{4}  = x \\ 81 = x
7)
 log_{5}(x)  +  log_{5}(30)  = 3 \\  log_{5}(30x)  = 3 \\  {5}^{3}  = 30x \\ 125 = 30x \\ x =  \frac{125}{30}  \\ x =   \frac{25}{6}
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