document.write( "Question 806279: Can anybody solve log2 x + log2(x − 2) = 3 those are log base 2\r
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document.write( "I tried following instructions and end up with because they say I'm supposed to square the 3, but I don't know if that's right \n" );
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Algebra.Com's Answer #485764 by htmentor(1343)![]() ![]() You can put this solution on YOUR website! log(x) + log(x-2) = 3 \n" ); document.write( "Using the product rule we can write the LHS as log of the two factors: \n" ); document.write( "log(x(x-2)) = 3 \n" ); document.write( "To remove the logarithm, raise the terms on either side of the equation to the 2nd power: \n" ); document.write( "2^log(x(x-2) = 2^3 \n" ); document.write( "x^2 - 2x = 8 \n" ); document.write( "x^2 - 2x - 8 = 0 \n" ); document.write( "Factor: \n" ); document.write( "(x-4)(x+2) = 0 \n" ); document.write( "This gives two solutions, x=4 and x=-2 \n" ); document.write( "But since we can't take the logarithm of a negative number, the answer is x=4. \n" ); document.write( " |