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Solve for x and leave an exact answer

Solve for x and leave an exact answer-example-1
User Clever
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1 Answer

5 votes

log_(2) x + log_(2) (x-7) = 3

log_(2) (x)(x-7) = 3

2^{ log_(2) (x)(x-7)} = 2^(3)

x(x-7) = 8

x^(2) - 7x -8 = 0

\left \{ {{ x_(1) = 8} \atop { x_(2) =-1}} \right.
Since in
log_(a) x x>0, then the answer is x=8 only.
Hope it helps!
User Hayes Haugen
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