document.write( "Question 463547: If 7x^2 + 4x = 3 , which of the following is (are) true?\r
\n" ); document.write( "\n" ); document.write( "I. The sum of the solutions is positive.
\n" ); document.write( "II. The product of the solutions is negative.
\n" ); document.write( "III. Both solutions are integers.\r
\n" ); document.write( "\n" ); document.write( "a) I only
\n" ); document.write( "b) II only
\n" ); document.write( "c) III only
\n" ); document.write( "d) I and II only
\n" ); document.write( "e) II and III only
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Algebra.Com's Answer #317629 by richard1234(7193)\"\" \"About 
You can put this solution on YOUR website!
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\n" ); document.write( "\n" ); document.write( "Know Vieta's formulas, which say that if you have a polynomial\r
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\n" ); document.write( "\n" ); document.write( "Then the sum of the roots is and the product of the roots is (plus, a whole bunch of other identities can be derived but we won't need them here).\r
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\n" ); document.write( "\n" ); document.write( "Here, the sum of the solutions is -4/7, which is not positive, so I is not true. The product of the solutions is (-3)/7, negative, so II is true. We automatically know III cannot be true since if both solutions were integers, their sum would be an integer, but we already know I is not true. Hence, only II is true; answer is B.\r
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\n" ); document.write( "\n" ); document.write( "For certain math problems, it can help to find a slick, fast solution. Here we were able to do it without even finding the roots of the quadratic.
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