document.write( "Question 261362: logbase10 x +logbase10 (x+21) = 2 \n" ); document.write( "
Algebra.Com's Answer #192548 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
logbase10 x +logbase10 (x+21) = 2
\n" ); document.write( "-------------
\n" ); document.write( "log(x) + log(x+21) = 2
\n" ); document.write( "---
\n" ); document.write( "log[x(x+21)] = 2
\n" ); document.write( "---
\n" ); document.write( "x(x+21) = 10^2
\n" ); document.write( "x^2+21x-100 = 0
\n" ); document.write( "(x+25)(x-4) = 0
\n" ); document.write( "Positive solution:
\n" ); document.write( "x = 4
\n" ); document.write( "====================
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H. \n" ); document.write( "
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