Question

Ecuaciones exponenciales y logarítmicas porfii

Answer 1

Respuesta:

1. x = 2

2. x = 2/7

3. x = 1

Explicación paso a paso:

Ejercicio 1

$3(4 - {3}^{x} ) = - 15$

$(4 - {3}^{x} ) = \frac{ - 15}{3}$

$4 - {3}^{x} = - 5$

$4 + 5 = {3}^{x}$

$9 = {3}^{x}$

${3}^{2} = {3}^{x}$

$2 = x$

$x = 2$

Ejercicio 2

${128}^{x} + 5 = 9$

${128}^{x} = 9 - 5$

${({2}^{7}) }^{x} = 4$

${2}^{7x} = {2}^{2}$

$7x = 2$

$x = \frac{2}{7}$

Ejercicio 3

$15 = {4}^{2x} - 1$

$15 + 1 = {4}^{2x}$

$16 = {4}^{2x}$

${4}^{2} = {4}^{2x}$

$2 = 2x$

$\frac{2}{2} = x$

$1 = x$

$x = 1$