document.write( "Question 319944: Please help me solve this equation: 2log7(x-1)=4log7(2) \n" ); document.write( "
Algebra.Com's Answer #229137 by ankor@dixie-net.com(22740)\"\" \"About 
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2log7(x-1)=4log7(2)
\n" ); document.write( "Use the exponent form
\n" ); document.write( "log7((x-1)^2) = log7(2^4)
\n" ); document.write( "FOIL
\n" ); document.write( "log7(x^2-2x+1) = log7(16)
\n" ); document.write( "Therefore:
\n" ); document.write( "x^2 - 2x + 1 = 16
\n" ); document.write( ":
\n" ); document.write( "x^2 - 2x + 1 - 16 = 0
\n" ); document.write( ":
\n" ); document.write( "x^2 - 2x - 15 = 0
\n" ); document.write( "Factor
\n" ); document.write( "(x-5)(x+3) = 0
\n" ); document.write( "Two solutions, but only the positive solution will work here
\n" ); document.write( "x = 5
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "You can confirm this:
\n" ); document.write( "log7((5-1)^2) = log7(2^4)
\n" ); document.write( "log7(4^2) = log7(16)\r
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