Math, asked by Anonymous, 18 days ago

answer this question refer the attachment​

Attachments:

Answers

Answered by mathdude500
15

\large\underline{\sf{Solution-}}

Given Logarithmic equation is

\rm :\longmapsto\: log_{2}(8y + 1) - 2 log_{2}(y - 1)  = 3 -  log_{2}(y + 4)

can be re-arranged as

\rm :\longmapsto\: log_{2}(8y + 1) - 2 log_{2}(y - 1) + log_{2}(y + 4) = 3

We know,

\boxed{ \tt{ \: xlogy = log {y}^{x} \: }}

So, using this identity, we get

\rm :\longmapsto\: log_{2}(8y + 1) -  log_{2}(y - 1)^{2}  + log_{2}(y + 4) = 3

We know,

\boxed{ \tt{ \: logx + logy = log(xy) \: }}

So, using this, we get

\rm :\longmapsto\: log_{2}[(8y + 1)(y + 4)] -  log_{2}(y - 1)^{2} = 3

We know,

\boxed{ \tt{ \: logx - logy = log \frac{x}{y} \: }}

So, using this, we get

\rm :\longmapsto\: log_{2}\bigg[\dfrac{(8y + 1)(y + 4)}{ {(y - 1)}^{2} } \bigg] = 3

We know,

\boxed{ \tt{ \:  log_{x}(y) = z \: \rm \implies\:y =  {x}^{z} \: }}

So, using this, we get

\rm :\longmapsto\:\dfrac{(8y  + 1)(y + 4)}{ {(y - 1)}^{2} }  =  {2}^{3}

\rm :\longmapsto\:(8y  +  1)(y + 4) = 8 {(y - 1)}^{2}

\rm :\longmapsto\: {8y}^{2} + 32y + 4 + y = 8( {y}^{2} - 2y + 1)

\rm :\longmapsto\: {8y}^{2} + 33y + 4 = 8{y}^{2} - 16y +8

\rm :\longmapsto\:  33y  + 16y=  8 - 4

\rm :\longmapsto\:  49y =  4

\bf\implies \:\boxed{ \tt{ \: y = \dfrac{4}{49}  \: }}

More to know :-

\boxed{ \tt{ \:  log_{x}(x) = 1 \: }}

\boxed{ \tt{ \:  log_{ {x}^{y} }( {x}^{z} ) =  \frac{z}{y} \: }}

\boxed{ \tt{ \: log {e}^{x}  = x \: }}

\boxed{ \tt{ \:  {e}^{logx} = x \: }}

\boxed{ \tt{ \:  {e}^{y \: logx} =  {x}^{y} \: }}

\boxed{ \tt{ \:  {a}^{ log_{a}(x) }  = x \: }}

\boxed{ \tt{ \:  {a}^{ y \: log_{a}(x) }  =  {x}^{y}  \: }}

Similar questions