document.write( "Question 609668: Hi, I have a question.\r
\n" ); document.write( "\n" ); document.write( "(2(cubedroot of a^2)) / (squareroot of 8a) =\r
\n" ); document.write( "\n" ); document.write( "I know that the answer is:\r
\n" ); document.write( "\n" ); document.write( "(fifthroot of (a/8))\r
\n" ); document.write( "\n" ); document.write( "I just don't understand how to get this??\r
\n" ); document.write( "\n" ); document.write( "Thanks!
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Algebra.Com's Answer #383887 by jsmallt9(3758)\"\" \"About 
You can put this solution on YOUR website!
\"%282%28root%283%2C+a%5E2%29%29%29%2F%28sqrt%288a%29%29\"
\n" ); document.write( "Keys to this problem are:
  • Understanding that roots/radicals can be replaced with fractional exponents.
  • 8 is a power of 2.
First let's rewrite 8 as \"2%5E3\" and 2 as \"2%5E1\":
\n" ); document.write( "\"%282%5E1%2A%28root%283%2C+a%5E2%29%29%29%2F%28sqrt%282%5E3%2Aa%29%29\"
\n" ); document.write( "Replacing the radicals with their fractional exponent equivalent:
\n" ); document.write( "\"%282%5E1%2A%28a%5E2%29%5E%281%2F3%29%29%2F%282%5E3%2Aa%29%5E%281%2F2%29\"
\n" ); document.write( "Now we use our rules for exponents to simplify:
\n" ); document.write( "\"%282%5E1%2Aa%5E%282%2F3%29%29%2F%282%5E3%2Aa%29%5E%281%2F2%29\" Rule: Multiply when raising a power to a power
\n" ); document.write( "\"%282%5E1%2Aa%5E%282%2F3%29%29%2F%28%282%5E3%29%5E%281%2F2%29%2Aa%5E%281%2F2%29%29\" Rule: (a*b)^q = a^q*b*q
\n" ); document.write( "\"%282%5E1%2Aa%5E%282%2F3%29%29%2F%282%5E%283%2F2%29%2Aa%5E%281%2F2%29%29\" Rule: Power of a power
\n" ); document.write( "\"2%5E%281-%283%2F2%29%29%2Aa%5E%28%282%2F3%29-%281%2F2%29%29\" Rule: Subtract exp. when dividing
\n" ); document.write( "\"2%5E%28-%281%2F2%29%29%2Aa%5E%281%2F6%29\"
\n" ); document.write( "\"a%5E%281%2F6%29%2F2%5E%281%2F2%29\" Rule: Negative exponents
\n" ); document.write( "\"a%5E%281%2F6%29%2F2%5E%283%2F6%29\" Match the denominators in the exponents
\n" ); document.write( "\"root%286%2C+a%29%2Froot%286%2C+2%5E3%29\" Rule: \"a%5E%28t%2Fu%29+=+root%28u%2C+a%5Et%29\"
\n" ); document.write( "\"root%286%2C+a%29%2Froot%286%2C+8%29\"
\n" ); document.write( "\"root%286%2C+a%2F8%29\" Rule: \"root%28a%2C+p%29%2Froot%28a%2C+q%29+=+root%28a%2C+p%2Fq%29\"
\n" ); document.write( "So the answer is the 6th root of a/8, not the 5th root.
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