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woodyp20
Feb 16, 2011, 11:28 PM
Solve the equation.
log2 x^2 = log2 (3x + 18)

Use natural logarithms to evaluate the logarithm to the nearest hundredth.
log square root of 5, 31.2

dancerintherain
Feb 17, 2011, 04:44 AM
log_2 x^2 = log_2 (3x+18)

log_2 x^2 - log_2 (3x+18)=0

log_2 \frac{x^2}{3x+18}=0

\frac{x^2}{3x+18}=1

Now it is just a simple equation. Good luck! :)

Unknown008
Feb 17, 2011, 07:44 AM
One shortcut maybe, but you have to make sure that you have only log on both sides and not log (something) plus/minus/etc (something else)

\log_2(x^2) = \log_2(3x +18)

Remove both logs,

x^2 = 3x + 18

And then solve.


For the second question, is that:

\log_{\sqrt5}(31.2) = ?

?