document.write( "Question 559993: I need help solving this problem:
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\n" ); document.write( "I've already factored out the y, but after that I'm not sure what I'm supposed to do, I used the quadratic formula but I get two answers: y(4)=0 and y(-1/7)=0
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Algebra.Com's Answer #363610 by Edwin McCravy(20056)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "You are supposed to find all values of y which, when substituted\r\n" );
document.write( "for y, the equation is true, i.e., it comes out 0 = 0.\r\n" );
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document.write( " 7y³ - 27y² - 4y = 0\r\n" );
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document.write( "Factor out the y, and you have this:\r\n" );
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document.write( "y(7y² - 27y - 4) = 0\r\n" );
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document.write( "Now factor the expression in the parentheses:\r\n" );
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document.write( "y(y - 4)(7y + 1) = 0\r\n" );
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document.write( "Since the right sides is 0, any one of those three factors \r\n" );
document.write( "on the left can equal 0 and the equation will be true.\r\n" );
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document.write( "The first factor on the left is y.\r\n" );
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document.write( "So y = 0 is a solution\r\n" );
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document.write( "The second factor on the left is y - 4\r\n" );
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document.write( "We set it = 0 and get y = 4\r\n" );
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document.write( "So y = 4 is also a solution.\r\n" );
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document.write( "The third factor on the left is 7y + 1\r\n" );
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document.write( "We set it = 0 and get y = \"-1%2F7\"\r\n" );
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document.write( "So y = \"-1%2F7\" is also a solution.\r\n" );
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document.write( "Therefore there are three values of y which,\r\n" );
document.write( "when substituted for y in the equation\r\n" );
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document.write( "7y³ - 27y² - 4y = 0\r\n" );
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document.write( "the equation is true, i.e., it comes out 0 = 0.\r\n" );
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document.write( "So the three solutions are \r\n" );
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document.write( "0, 4, and \"-1%2F7\"\r\n" );
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document.write( "Edwin
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