SOLUTION: log2(x+3)+log2x=2

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Question 870165: log2(x+3)+log2x=2
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
log%282%2C%28x%2B3%29%29+%2B+log%282%2Cx%29+=+2
Adding logs --> multiplication
log%282%2Cx%2A%28x%2B3%29%29+=+2
log%282%2C%28x%5E2%2B3x%29%29+=+2
Then,
log%282%2C%28x%5E2%2B3x%29%29+=+log%282%2C4%29
x%5E2%2B3x+=+4
Now it's a quadratic.
Check both zeroes, don't accept the log of a negative number.