document.write( "Question 927887: solve the following equation log3 (x+4)+log3 (x-2)=3 \n" ); document.write( "
Algebra.Com's Answer #563313 by rothauserc(4718)\"\" \"About 
You can put this solution on YOUR website!
log3 (x+4) + log3 (x-2) = 3
\n" ); document.write( "us logarithm rule for adding logs with same base
\n" ); document.write( "log3 ( (x+4) * (x-2) ) = 3
\n" ); document.write( "log3 ( x^2 +2x -8 ) = 3
\n" ); document.write( "us definition of logarithm
\n" ); document.write( "x^2 +2x -8 = 3^3
\n" ); document.write( "x^2 +2x -8 = 27
\n" ); document.write( "x^2 +2x -35 = 0
\n" ); document.write( "factor polynomial
\n" ); document.write( "(x+7)*(x-5) = 0
\n" ); document.write( "x = -7 and 5
\n" ); document.write( "now the log of a negative number is not defined, therefore
\n" ); document.write( "x = 5
\n" ); document.write( "check answer
\n" ); document.write( "log3 (5+4) + log3 (5-2) = 3
\n" ); document.write( "2 + 1 = 3
\n" ); document.write( "3 = 3
\n" ); document.write( "answer checks\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "
\n" );