document.write( "Question 358461: Solve: 81x^2-72xy+16y^2 Thank you so much! I really appreciate it! \n" ); document.write( "
Algebra.Com's Answer #255832 by Edwin McCravy(20086)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "Factor, not \"solve\".  \"Solve\" means to find the numerical values of the\r\n" );
document.write( "variables, which is not possible when you only have an expression and\r\n" );
document.write( "not an equation.  So we will factor this:\r\n" );
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document.write( "81x² - 72xy + 16y²\r\n" );
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document.write( "Since the first term and last term are both perfect squares,\r\n" );
document.write( "of 9x and 4y try this factorization:\r\n" );
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document.write( "(9x   4y)(9x   4y)\r\n" );
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document.write( "Then you can see there would have to be a - sign in each, so\r\n" );
document.write( "the factorization becomes:\r\n" );
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document.write( "(9x - 4y)(9x - 4y)\r\n" );
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document.write( "and since those factors are the same, we can simplify by writing\r\n" );
document.write( "it as\r\n" );
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document.write( "(9x - 4y)²\r\n" );
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document.write( "That's the final answer.  Notice you didn't \"solve\" anything because\r\n" );
document.write( "you still don't know any particular value that x must equal or that y \r\n" );
document.write( "must equal.  You factored the expression, but you didn't \"solve\"\r\n" );
document.write( "anything.\r\n" );
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document.write( "Edwin
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