document.write( "Question 111367: Prove a^3-64/a^2-16=a^2+4a+16/a+4 \n" ); document.write( "
Algebra.Com's Answer #81187 by jim_thompson5910(35256)\"\" \"About 
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For this problem we need to use the difference of squares and the difference of cubes formulas. \r
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\n" ); document.write( "\n" ); document.write( "Remember the difference of squares formula is:\r
\n" ); document.write( "\n" ); document.write( "\"x%5E2-y%5E2=%28x%2By%29%28x-y%29\"\r
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\n" ); document.write( "\n" ); document.write( "and the difference of cubes formula is:\r
\n" ); document.write( "\n" ); document.write( "\"x%5E3-y%5E3=%28x-y%29%28x%5E2%2Bxy%2By%5E2%29\"\r
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\n" ); document.write( "\n" ); document.write( "So rewrite the numerator \"a%5E3-64\" as \"%28a%29%5E3-%284%29%5E3\" notice how \"x=a\" and \"y=b\" for the formula \"x%5E2-y%5E2=%28x%2By%29%28x-y%29\". Now factor \"%28a%29%5E3-%284%29%5E3\" to \"%28a-4%29%28a%5E2%2B4a%2B16%29\"\r
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\n" ); document.write( "\n" ); document.write( "So our expression now looks like this: \"%28a-4%29%28a%5E2%2B4a%2B16%29%2F%28a%5E2-16%29\"\r
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\n" ); document.write( "\n" ); document.write( "Now factor the denominator using the difference of squares\r
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\n" ); document.write( "\n" ); document.write( "\"%28a-4%29%28a%5E2%2B4a%2B16%29%2F%28%28a%2B4%29%28a-4%29%29\"\r
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\n" ); document.write( "\n" ); document.write( "Cancel like terms\r
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\n" ); document.write( "\n" ); document.write( "\"cross%28%28a-4%29%29%28a%5E2%2B4a%2B16%29%2F%28%28a%2B4%29cross%28%28a-4%29%29%29\"\r
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\n" ); document.write( "\n" ); document.write( "Simplify\r
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\n" ); document.write( "\n" ); document.write( "\"%28a%5E2%2B4a%2B16%29%2F%28a%2B4%29\"\r
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\n" ); document.write( "\n" ); document.write( "So this shows that \"%28a%5E3-64%29%2F%28a%5E2-16%29\" simplifies to \"%28a%5E2%2B4a%2B16%29%2F%28a%2B4%29\"
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