document.write( "Question 576368: \"Solve the equation.\"\r
\n" ); document.write( "\n" ); document.write( "\"log\"_7 1/49 = x
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Algebra.Com's Answer #369820 by Alan3354(69443) $\"\"$ $\"About$

You can put this solution on YOUR website!
\"Solve the equation.\"\r
\n" ); document.write( "\n" ); document.write( "\"log\"_7 1/49 = x
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\n" ); document.write( "The \"'s don't contribute anything.
\n" ); document.write( " $\"log%287%2C1%2F49%29+=+x\"$
\n" ); document.write( "Solve for x, right?
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\n" ); document.write( "1st approach is to recognize that 49 = 7^2, so 1/49 = 7^-2
\n" ); document.write( "--> x = -2
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\n" ); document.write( "Or use the base change formula.
\n" ); document.write( "x = log(1/49)/log(7)
\n" ); document.write( "x = -2
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\n" ); document.write( "The base change formula always works.
\n" ); document.write( "If it were $\"log%287%2C1%2F48%29+=+x\"$ you couldn't use the 1st method.\r
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