Question

1.log3(2x+5)=2 2.log2(x2-2x)-3=2 3.log(x-1)(X+5)=2 4.LOGx(5x-6)-2=0 5.log(x+5)2-log(x+5)=2 6.3log(5-x)=log(35-X3) 7.2logX-3logX/2=log4

Answer 1

1. $<var>\begin{gathered} {\log _3}\left( {2x + 5} \right) = 2 \hfill \\ \Rightarrow \frac{{\log \left( {2x + 5} \right)}}{{\log 3}} = 2 \hfill \\ \Rightarrow \log \left( {2x + 5} \right) = 2\log 3 = \log {3^2} \hfill \\ \Rightarrow \log \left( {2x + 5} \right) = \log 9 \hfill \\ \Rightarrow 2x + 5 = 9 \hfill \\ \Rightarrow 2x = 4 \hfill \\ \Rightarrow x = 2 \hfill \\ \end{gathered} </var>$

 

3. $<var>\[\begin{gathered} \log \left[ {\left( {x - 1} \right)\left( {x + 5} \right)} \right] = 2 \hfill \\ </var><var>\Rightarrow \log \left[ {\left( {x - 1} \right)\left( {x + 5} \right)} \right] = \log 100 \hfill \\ \Rightarrow \left( {x - 1} \right)\left( {x + 5} \right) = 100 \hfill \\ \Rightarrow {x^2} + 4x - 5 = 100 \hfill \\ \Rightarrow {x^2} + 4x - 105 = 0 \hfill \\ \Rightarrow x = - 2 + \sqrt {109} \vee x = - 2 - \sqrt {109} \hfill \\ \end{gathered} </var>$

 

las otras se hacen igual...

 

Answer 2

Respuesta:

yo lo hice así

log 3 (2x+5)=2

3²=2x+5

9=2x+5

9-5=2x

4=2x

x=2

Explicación paso a paso:

me salio igual que el de arriba