SOLUTION: sample final question...trying to study correctly for final : solve each equation: log (7x+8) = 2 log x THANK U THANK U THANK U

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Question 139969: sample final question...trying to study correctly for final :
solve each equation:
log (7x+8) = 2 log x
THANK U THANK U THANK U
Answer by Earlsdon(6103) About Me  (Show Source):
You can put this solution on YOUR website!
Solve for x:
log%28%287x%2B8%29%29+=+2%2Alog%28%28x%29%29 Apply the power rule to the right side.
log%28%287x%2B8%29%29+=+log%28%28x%5E2%29%29 Now, if Log%5Bb%5D%28M%29+=+Log%5Bb%5D%28N%29 then M+=+N, so...
7x%2B8+=+x%5E2 Subtract 7x+8 from both sides.
x%5E2-7x-8+=+0 Factor the trinomial.
x%2B1%29%28x-8%29+=+0 Apply the zero product rule:
x%2B1+=+0 or x-8+=+0, so...
x+=+-1 or x+=+8