document.write( "Question 426986: What two factors multiply to equaul 72 but add up to be negative 18? \n" ); document.write( "

Algebra.Com's Answer #296972 by htmentor(1343) $\"\"$ $\"About$

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x*y = 72
\n" ); document.write( "x + y = -18 -> y = -18 - x
\n" ); document.write( "Substitute in the 1st equation:
\n" ); document.write( "x*(-18 - x) = 72 -> -x^2 - 18x - 72 = 0 -> x^2 + 18x + 72 = 0
\n" ); document.write( "Quadratic formula gives:
\n" ); document.write( " $\"x+=+%28-18+%2B-+sqrt%2818%5E2+-+4%2A%2872%29%29%29%2F2\"$
\n" ); document.write( "Solving for x gives:
\n" ); document.write( "x = -6,-12
\n" ); document.write( "Therefore, y = -18 - -6 = -12 or y = -18 - -12 = -6.
\n" ); document.write( "So the two numbers are: -6,-12 \n" ); document.write( "

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