SOLUTION: 8^2x-1=90 I need this to the nearest thousandths

Algebra ->  Exponential-and-logarithmic-functions -> SOLUTION: 8^2x-1=90 I need this to the nearest thousandths      Log On


   

Question 383530: 8^2x-1=90 I need this to the nearest thousandths
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Solve for x, to the nearest thousandth.
8%5E%282x-1%29+=+90 Is this right? Take the log of both sides.
Log%288%5E%282x%29%29+=+Log%2890%29 Apply the power rule to the left side.
2x%2ALog%288%29+=+Log%2890%29 Divide both sides by Log%288%29
2x+=+Log%2890%29%2FLog%288%29 Evaluate the right side.
2x+=+1.0269 Divide both sides by 2.
x+=+0.513