SOLUTION: log2x+log2(x-6)=4

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Question 22137: log2x+log2(x-6)=4
Answer by longjonsilver(2297) About Me  (Show Source):
You can put this solution on YOUR website!
i assume the 2 is the base of the log. You should explain. I shall leave the 2 out, for ease of writing...

log(x)+log(x-6)=4

To remove log-base 2, we need to raise the left and right hand terms to power 2. We can only do that easily when we have 1 term on both sides, so first we re-write the equation as:

log((x)(x-6))=4

And now we raise to power 2, giving

%28x%29%28x-6%29=4%5E2
x%5E2-6x=16
x%5E2-6x-16+=+0
(x-8)(x+2) = 0

so either x=8 or x=-2

jon.