SOLUTION: log3 4x + log3 (x-4) = 2

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Question 309262: log3 4x + log3 (x-4) = 2
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Solve for x:
Log%5B3%5D%284x%29%2BLog%5B3%5D%28x-4%29+=+2 Apply the "product rule" for logarithms.
Log%5B3%5D%28%284x%29%28x-4%29%29+=+2 Multiply the arguments.
Log%5B3%5D%284x%5E2-16x%29+=+2 Rewrite in exponential form.
3%5E2+=+4x%5E2-16x Write this as a quadratic equation in standard form.
4x%5E2-16x-9+=+0 Solve by factoring.
%282x-9%29%282x%2B1%29+=+0 Apply the "zero product" rule.
2x-9+=+0 or 2x%2B1+=+0 so...
2x+=+9 or 2x+=+-1 and...
highlight%28x+=+9%2F2%29 or highlight%28x+=+-1%2F2%29