document.write( "Question 80419: Solve for x\r
\n" ); document.write( "\n" ); document.write( "(1/7)^x=49 \n" ); document.write( "

Algebra.Com's Answer #57697 by Earlsdon(6294) $\"\"$ $\"About$

You can put this solution on YOUR website!
Solve for x:
\n" ); document.write( " $\"%281%2F7%29%5Ex+=+49\"$ But $\"49+=+7%5E2\"$ = $\"1%2F7%5E%28-2%29+=+%281%2F7%29%5E-2\"$ , so we get:
\n" ); document.write( " $\"%281%2F7%29%5Ex+=+%281%2F7%29%5E-2\"$ , therefore x = -2\r
\n" ); document.write( "\n" ); document.write( "If you are not comfortable with this approach, here's another one:
\n" ); document.write( " $\"%281%2F7%29%5Ex+=+49\"$ Take the logarithm of both sides.
\n" ); document.write( " $\"Log%5B10%5D%281%2F7%29%5Ex+=+Log%5B10%5D%2849%29\"$ Apply the power rule to the left side.
\n" ); document.write( " $\"x%2ALog%5B10%5D%281%2F7%29+=+Log%5B10%5D%2849%29\"$ Divide both sides by $\"Log%5B10%5D%281%2F7%29\"$
\n" ); document.write( " $\"x+=+%28Log%5B10%5D%2849%29%29%2FLog%5B10%5D%281%2F7%29\"$ Do this with your calculator.
\n" ); document.write( " $\"x+=+-2\"$ \n" ); document.write( "

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