document.write( "Question 507655: two numbers whose sum is 21 and whose product is 90 \n" ); document.write( "

Algebra.Com's Answer #340645 by oberobic(2304) $\"\"$ $\"About$

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x + y = 21
\n" ); document.write( "so
\n" ); document.write( "x = 21-y
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\n" ); document.write( "x * y = 90
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\n" ); document.write( "(21-y) * y = 90
\n" ); document.write( "21y - y^2 = 90
\n" ); document.write( "-y^2 +21y - 90 = 0
\n" ); document.write( "y^2 -21y + 90 = 0
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\n" ); document.write( "(y -6)(y -15) = 0
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\n" ); document.write( "y = 6 or 15
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\n" ); document.write( "which means
\n" ); document.write( "x = 15 or 6, respectively, to make the sum = 21.
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\n" ); document.write( "The two numbers are 6 and 15.
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\n" ); document.write( "Done. \n" ); document.write( "

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