Math, asked by rohan34589, 11 months ago

log2 x + log2 (x + 2) = 3​

Answers

Answered by waqarsd
5

Step-by-step explanation:

 log_{2}(x) +  log_{2}(x + 2)  = 3 \\  \\  log_{2}(x(x + 2))  = 3 log_{2}(2)  \\  \\  log_{2}( {x}^{2} + 2x )  =  log_{2}( {2}^{3} )  =  log_{2}(8)  \\  \\  {x}^{2}  + 2x = 8 \\  \\  {x}^{2}   + 2x - 8 = 0 \\  \\  {x}^{2}  + 4x - 2x - 8 = 0 \\  \\ x(x + 4) - 2(x + 4) = 0 \\  \\ (x - 2)(x + 4) = 0 \\  \\ x + 4 \neq0 \:  \: as \: x + 2 > 0 \\  \\ so \\  \\ x = 2 \\  \\ formulae \\  \\  log_{a}(x)  +   log_{a}(y)  =  log_{a}(xy)  \\  \\  log_{a}(a)  = 1 \\  \\ m log_{a}(x)  =  log_{a}( {x}^{m} )  \\  \\ if \:  \:  log_{a}(x)  =  log_{a}(y)   \\  \\ then \:  \: x = y \\  \\ and \\  \\ a > 1 \:  \: for \: all \\

Hope it helps

Answered by adrija70
0

Answer:

x = 10, or x = e

Step-by-step explanation:

log2x + log2(x+2) = 3

=> log2 + logx + log2x + log 4 = 3

=> 0.301 + logx + log2 + logx + 2log2 = 3

=> 0.301 + logx +0.301 + logx + 0.602 = 3

=> 2logx + 1.204 = 3

=> 2logx = 1.796

=> logx = 0.898

Now, we can assume, 0.898 is nearly equal to 1

=> log x = 1

=> x = 10¹ [ if log base is 10]

=> x = 10

Now, if log base is e, then,

=> log x = 1

=> x = e¹

=> x = e

Hope it helps. If it helps, then you may mark it brainliest.

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