document.write( "Question 1105525: The sum of the square of two number is 65 and the square of their sum is 121. Find the numbers\r
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Algebra.Com's Answer #720371 by rothauserc(4718)\"\" \"About 
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1) x^2 + y^ 2 = 65
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\n" ); document.write( "2) (x + y)^2 = 121
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\n" ); document.write( "using equation 2, square the left side of =
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\n" ); document.write( "3) x^2 + 2xy +y^2 = 121
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\n" ); document.write( "use equation 1 and substitute for x^2 + y^2 in equation 3
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\n" ); document.write( "2xy + 65 = 121
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\n" ); document.write( "2xy = 56
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\n" ); document.write( "xy = 28
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\n" ); document.write( "x = 28/y
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\n" ); document.write( "substitute for x in equation 1
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\n" ); document.write( "28^2/y^2 + y^2 = 65
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\n" ); document.write( "784 + y^4 = 65y^2
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\n" ); document.write( "let u = y^2, then
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\n" ); document.write( "u^2 -65u +784 = 0
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\n" ); document.write( "(u-16) * (u-49) = 0
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\n" ); document.write( "u = 16 or u = 49
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\n" ); document.write( "Note that u = y^2, so y = 4,-4 or 7,-7
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\n" ); document.write( "the numbers are 4 and 7 or -4 and -7
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