document.write( "Question 76737: Factor: 15 + 3y – 5x2 – x2y \n" ); document.write( "

Algebra.Com's Answer #55040 by jim_thompson5910(35256) $\"\"$ $\"About$

You can put this solution on YOUR website!
$\"15+%2B+3y+-+5x%5E2+-+x%5E2y+\"$ Start with the given problem
\n" ); document.write( " $\"%2815+%2B+3y%29+%2B+%28-+5x%5E2+-+x%5E2y%29+\"$ group like terms
\n" ); document.write( " $\"3%285+%2B+y%29+-x%5E2%285+%2B+y%29+\"$ Factor out a 3 out of the first group. Factor out a $\"-x%5E2\"$ our of the second group.
\n" ); document.write( "Notice we have a common term of (5+y). If we let w=5+y we get
\n" ); document.write( " $\"3w-x%5E2w\"$ Since we have a common term of w, we can combine these terms
\n" ); document.write( " $\"%283-x%5E2%29w\"$ Combine like terms
\n" ); document.write( " $\"%283-x%5E2%29%285%2By%29\"$ replace w with 5+y
\n" ); document.write( "So $\"15+%2B+3y+-+5x%5E2+-+x%5E2y+\"$ factors to $\"%283-x%5E2%29%285%2By%29\"$
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\n" ); document.write( "Check:
\n" ); document.write( "If we foil $\"%283-x%5E2%29%285%2By%29\"$ we should get $\"15+%2B+3y+-+5x%5E2+-+x%5E2y+\"$ again.\r
\n" ); document.write( "\n" ); document.write( " $\"%283-x%5E2%29%285%2By%29\"$ foil
\n" ); document.write( " $\"%283-x%5E2%29%285%2By%29=3%2A5%2B3y-5x%5E2-x%5E2y=15%2B3y-5x%5E2-x%5E2y\"$ so this supports our answer \n" ); document.write( "

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