document.write( "Question 1098844: Hi,\r
\n" ); document.write( "\n" ); document.write( "I would appreciate if someone might help here.\r
\n" ); document.write( "\n" ); document.write( "Exercise instructions: Express following in form X + Y*2^(1/2); X and Y are rational numbers:\r
\n" ); document.write( "\n" ); document.write( " (7 + 5 * 2^(1/2))^(1/3) \r
\n" ); document.write( "\n" ); document.write( "The answer given is: 1 + 2^(1/2)\r
\n" ); document.write( "\n" ); document.write( "I have no idea how they got there.\r
\n" ); document.write( "\n" ); document.write( "Thanks
\n" ); document.write( "

Algebra.Com's Answer #713242 by KMST(5328)\"\" \"About 
You can put this solution on YOUR website!
If we are not given the solution, we just need to solve
\n" ); document.write( "\"%28X%2BY%2A2%5E%281%2F2%29%29%5E3=7%2B5%2A2%5E%281%2F2%29\" .
\n" ); document.write( "If you like square roots better than fractional exponents,
\n" ); document.write( "feel free to write \"2%5E%221+%2F+2%22\" as \"sqrt%282%29\" .
\n" ); document.write( "I will have to write \"1%2F2\" as \"%221%2F2%22\" in some places,
\n" ); document.write( "to make sure that you see the whole fractional exponent,
\n" ); document.write( "because I do not see the whole exponent in \"2%5E%281%2F2%29\" .
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\n" ); document.write( "\"X%5E3%2B6XY%5E2-7%2B%283X%5E2Y%2B2Y%5E3-5%29%2A2%5E%221%2F2%22=0\"
\n" ); document.write( "Now we only need the one and only rational pair solution to
\n" ); document.write( "\"system%28X%5E3%2B6XY%5E2-7=0%2C3X%5E2%2B2Y%5E3-5=0%29\" .
\n" ); document.write( "When looking for rational solutions for polynomial equations,
\n" ); document.write( "we just try numbers that look promising.
\n" ); document.write( "Substituting \"system%28X=1%2CY=1%29\" in those two equations,
\n" ); document.write( "we find that they are a solution.
\n" ); document.write( "Knowing that there was only one real solution to be found,
\n" ); document.write( "we know that \"system%28X=1%2CY=1%29\" gives us
\n" ); document.write( "THE one and only answer, which is
\n" ); document.write( "\"highlight%281%2B2%5E%221%2F2%22%29\" , also known as \"1%2Bsqrt%282%29\" .
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\n" ); document.write( "NOTE: If the question was stated as \"prove that \"%287%2B5%2A2%5E%281%2F2%29%29%5E%281%2F3%29+=1%2B2%5E%281%2F2%29\" ,\" all we would have needed to do is calculate
\n" ); document.write( "\"%281%2B2%5E%221%2F2%22%29%5E3\" , by expanding that cube of a binomial,
\n" ); document.write( "and simplifying as needed.
\n" ); document.write( "As asked, the problem was not as difficult as it was intimidating,
\n" ); document.write( "encouraging you to give up.
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