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Mathematics 8 Online
OpenStudy (anonymous):

can someone check this out?

OpenStudy (anonymous):

What?

OpenStudy (anonymous):

\[2\log_{2}x-\log_{2}(x+3)=2\]

OpenStudy (anonymous):

i got \[x=2/\log_{2}(x+3) \] i just need to see if its correct?

OpenStudy (anonymous):

noit is not correct

OpenStudy (anonymous):

means solve for x, yes?

OpenStudy (anonymous):

yes.

OpenStudy (anonymous):

ok first combine the left hand side into one logarithm using things like\[log(A) + log(B) = log(AB)\]

OpenStudy (anonymous):

first \[2log_2(x)=log_2(x^2)\]

OpenStudy (anonymous):

then \[log_2(x^2)-log_2(x+3)=log_2(\frac{x^2}{x+3})\]

OpenStudy (anonymous):

so we have \[log_2(\frac{x^2}{x+3})=2\] in equivalent exponential form this means \[\frac{x^2}{x+3}=2^2=4\]

OpenStudy (anonymous):

\[x^2=4(x+3)\] \[x^2=4x+12\] \[x^2-4x-12=0\]

OpenStudy (anonymous):

\[(x-6)(x+2)=0\] \[x=6\]or \[x=-2\] but we throw out the -2 because you cannot take the log of a negative number. so answer is \[x=6\]

OpenStudy (anonymous):

hope the steps are clear.

OpenStudy (anonymous):

thank you..

OpenStudy (anonymous):

welcome!

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