document.write( "Question 1153085: Determine the value of ab if https://imgur.com/a/1u4d55h \n" ); document.write( "
Algebra.Com's Answer #775243 by greenestamps(13203)\"\" \"About 
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\n" ); document.write( "\"log%288%2Ca%29%2Blog%284%2Cb%5E2%29+=+5\"
\n" ); document.write( "\"log%288%2Cb%29%2Blog%284%2Ca%5E2%29+=+7\"

\n" ); document.write( "Change the bases of each logarithm, knowing that \"2%5E2=4\" and \"2%5E3=8\".

\n" ); document.write( "\"%281%2F3%29log%282%2Ca%29%2B%281%2F2%29log%282%2Cb%5E2%29+=+5\"
\n" ); document.write( "\"%281%2F3%29log%282%2Cb%29%2B%281%2F2%29log%282%2Ca%5E2%29+=+7\"

\n" ); document.write( "Simplify using the exponent rule of logarithms.

\n" ); document.write( "\"%281%2F3%29log%282%2Ca%29%2Blog%282%2Cb%29+=+5\"
\n" ); document.write( "\"%281%2F3%29log%282%2Cb%29%2Blog%282%2Ca%29+=+7\"

\n" ); document.write( "Change the two equations to exponential form. (See below for an alternative method for solving the problem from this point.)

\n" ); document.write( "\"a%5E%281%2F3%29%2Ab+=+2%5E5\"
\n" ); document.write( "\"b%5E%281%2F3%29%2Aa+=+2%5E7\"

\n" ); document.write( "Multiply the two equations together:

\n" ); document.write( "\"%28ab%29%5E%284%2F3%29+=+2%5E12\"
\n" ); document.write( "\"ab+=+2%5E9+=+512\"

\n" ); document.write( "ANSWER: ab = 512

\n" ); document.write( "It's more work; but you could also solve the problem by using elimination to solve the pair of equations in the two unknowns, \"log%282%2Ca%29\" and \"log%282%2Cb%29\".

\n" ); document.write( "\"3log%282%2Cb%29%2Blog%282%2Ca%29+=+15\"
\n" ); document.write( "\"%281%2F3%29log%282%2Cb%29%2Blog%282%2Ca%29+=+7\"
\n" ); document.write( "\"%288%2F3%29log%282%2Cb%29+=+8\"
\n" ); document.write( "\"log%282%2Cb%29+=+3\"
\n" ); document.write( "\"b+=+2%5E3+=+8\"

\n" ); document.write( "\"3log%282%2Ca%29%2Blog%282%2Cb%29+=+21\"
\n" ); document.write( "\"%281%2F3%29log%282%2Ca%29%2Blog%282%2Cb%29+=+5\"
\n" ); document.write( "\"%288%2F3%29log%282%2Ca%29+=+16\"
\n" ); document.write( "\"log%282%2Ca%29+=+6\"
\n" ); document.write( "\"a+=+2%5E6+=+64\"

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