document.write( "Question 682117: 7^12 - 4^12 is exactly divisible by
\n" ); document.write( "A.33
\n" ); document.write( "B.34
\n" ); document.write( "C.35
\n" ); document.write( "D.36\r
\n" ); document.write( "\n" ); document.write( "Explain how?
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Algebra.Com's Answer #423047 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "7^12 - 4^12 \r
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\n" ); document.write( "\n" ); document.write( "(7^6)^2 - (4^6)^2 \r
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\n" ); document.write( "\n" ); document.write( "(7^6 - 4^6)(7^6 + 4^6) ... Use the difference of squares rule\r
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\n" ); document.write( "\n" ); document.write( "((7^3)^2 - (4^3)^2)(7^6 + 4^6)\r
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\n" ); document.write( "\n" ); document.write( "(7^3 - 4^3)(7^3 + 4^3)(7^6 + 4^6) ... Use the difference of squares rule\r
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\n" ); document.write( "\n" ); document.write( "(7 - 4)(7^2 + 7*4 + 4^2)(7^3 + 4^3)(7^6 + 4^6) ... Use the difference of cubes rule\r
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\n" ); document.write( "\n" ); document.write( "(7 - 4)(49 + 28 + 16)(7^3 + 4^3)(7^6 + 4^6)\r
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\n" ); document.write( "\n" ); document.write( "(3)(93)(7^3 + 4^3)(7^6 + 4^6)\r
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\n" ); document.write( "\n" ); document.write( "(3)(93)(7 + 4)(7^2 - 7*4 + 4^2)(7^6 + 4^6) ... Use the sum of cubes rule\r
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\n" ); document.write( "\n" ); document.write( "(3)(93)(7 + 4)(49 - 28 + 16)(7^6 + 4^6)\r
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\n" ); document.write( "\n" ); document.write( "(3)(93)(11)(37)(7^6 + 4^6)\r
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\n" ); document.write( "\n" ); document.write( "(3*11)(93)(37)(7^6 + 4^6)\r
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\n" ); document.write( "\n" ); document.write( "(33)(93)(37)(7^6 + 4^6)\r
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\n" ); document.write( "\n" ); document.write( "We can see that 33 is a factor of (33)(93)(37)(7^6 + 4^6), so 33 is also a factor of 7^12 - 4^12 since each line in the work shown above is equivalent to any other line (ie they represent the same number)\r
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\n" ); document.write( "\n" ); document.write( "This means that 7^12 - 4^12 is exactly divisible by 33.\r
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\n" ); document.write( "\n" ); document.write( "Therefore, the answer is A) 33.\r
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