document.write( "Question 45878: Factor the polynomial completely.\r
\n" ); document.write( "\n" ); document.write( " $\"x%5E2-y%5E2%2B18y-81\"$ \n" ); document.write( "

Algebra.Com's Answer #30505 by Earlsdon(6294) $\"\"$ $\"About$

You can put this solution on YOUR website!
I provided a solution (# 29893) for this problem previously.\r
\n" ); document.write( "\n" ); document.write( "Factor completely:
\n" ); document.write( " $\"x%5E2-y%5E2%2B18y-81\"$ Group the last four terms.
\n" ); document.write( " $\"x%5E2-%28y%5E2-18y%2B81%29\"$ Note the change in sign due to the introduction of the parentheses. Now factor the parentheses. $\"%28y%5E2-18y%2B81%29+=+%28y-9%29%28y-9%29\"$ = $\"%28y-9%29%5E2\"$
\n" ); document.write( " $\"x%5E2-%28y-9%29%5E2\"$ You will notice that you now have the difference of two squares which will factor nicely.
\n" ); document.write( " $\"x%5E2-%28y-9%29%5E2+=+%28x%2B%28y-9%29%29%28x-%28y-9%29%29\"$ This can be simplified to:
\n" ); document.write( " $\"%28x%2By-9%29%28x-y%2B9%29\"$ These are the required factors.
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