document.write( "Question 838938: one of the roots of 3x^2+p=5x, is 2.determine the value of p and the other root \n" ); document.write( "
Algebra.Com's Answer #505431 by Theo(13342)\"\" \"About 
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if one of the roots of the equation is x = 2, then f(2) must be equal to 0.\r
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\n" ); document.write( "\n" ); document.write( "start with 3x^2 + p = 5x
\n" ); document.write( "subtract 5x from both sides of this equation to get:
\n" ); document.write( "3x^2 - 5x + p = 0
\n" ); document.write( "replace x with 2 in the equation to get:
\n" ); document.write( "3(2)^2 - 5(2) + p = 0
\n" ); document.write( "simplify this to get:
\n" ); document.write( "12 - 10 + p = 0
\n" ); document.write( "simplify further to get:
\n" ); document.write( "2 + p = 0
\n" ); document.write( "solve for p to get:
\n" ); document.write( "p = -2\r
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\n" ); document.write( "\n" ); document.write( "your expression becomes:
\n" ); document.write( "3x^2 - 5x - 2 = 0\r
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\n" ); document.write( "\n" ); document.write( "factor this equation to get:
\n" ); document.write( "(3x + 1) * (x-2) = 0
\n" ); document.write( "your factors will be:
\n" ); document.write( "x = 2
\n" ); document.write( "x = -1/3\r
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\n" ); document.write( "\n" ); document.write( "to confirm, replace x with -1/3 in the original equation to see if it holds true.\r
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\n" ); document.write( "\n" ); document.write( "original equation is:
\n" ); document.write( "3x^2 + p = 5x
\n" ); document.write( "replace p with -2 to get:
\n" ); document.write( "3x^2 - 2 = 5x
\n" ); document.write( "replace x with (-1/3) to get:
\n" ); document.write( "3(-1/3)^2 - 2 = 5*(-1/3)
\n" ); document.write( "simplify to get:
\n" ); document.write( "3 * 1/9 - 2 = -5/3
\n" ); document.write( "convert everything to a common denominator of 9 to get:
\n" ); document.write( "3/9 - 18/9 = -15/9
\n" ); document.write( "simplify to get:
\n" ); document.write( "-15/9 = -15/9
\n" ); document.write( "this confirms that -1/3 is a root of the equation.\r
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\n" ); document.write( "\n" ); document.write( "you can do the same with x = 2 to confirm it is also a solution to the equation.
\n" ); document.write( "original equation is:
\n" ); document.write( "3x^2 + p = 5x
\n" ); document.write( "replace p with -2 to get:
\n" ); document.write( "3x^2 - 2 = 5x
\n" ); document.write( "replace x with 2 to get:
\n" ); document.write( "3(2)^2 - 2 = 5*(2)
\n" ); document.write( "simplify to get:
\n" ); document.write( "12 - 2 = 10
\n" ); document.write( "simplify further to get:
\n" ); document.write( "10 = 10
\n" ); document.write( "this confirms that 2 is a root of the equation.\r
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