document.write( "Question 927517: Find all real values of b such that the equation: x^2 + bx + 6b = 0
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Algebra.Com's Answer #563014 by MathLover1(20849)\"\" \"About 
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Find all real values of \"b\" such that the equation: \r
\n" ); document.write( "\n" ); document.write( "\"x%5E2+%2B+bx+%2B+6b+=+0\" only has integer roots.\r
\n" ); document.write( "\n" ); document.write( "Theorem:
\n" ); document.write( "Let \"f%28x%29=ax%5E2+%2B+bx+%2B+c\", being a quadratic trinomial with integer coefficients \"a\", \"b\", \"c\". Then, both roots or zeros of \"f%28x%29\" are integers; if, and only if,
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\n" ); document.write( "The integer \"D=b%5E2-4ac\" is an integer or perfect square.
\n" ); document.write( "and
\n" ); document.write( "(ii) The leading coefficient \"a\" is a divisor of both \"b\" and \"c\". \r
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\n" ); document.write( "\n" ); document.write( "in your case, The leading coefficient \"a\" is a divisor of both \"b\" and \"c\" because \"a=1\" \r
\n" ); document.write( "\n" ); document.write( "but, we need \"b\"; so,\r
\n" ); document.write( "\n" ); document.write( "\"x%5E2+%2B+bx+%2B+6b+=+0+\" if discriminant \"D%3E0\" (Positive Discriminant ), we will have Two Real Solutions\r
\n" ); document.write( "\n" ); document.write( "\"D=b%5E2-4ac\"\r
\n" ); document.write( "\n" ); document.write( "\"b%5E2-4ac%3E0\"\r
\n" ); document.write( "\n" ); document.write( "\"b%5E2-4%2A1%2A6b%3E0\" ........solve for \"b\"\r
\n" ); document.write( "\n" ); document.write( "\"b%5E2-24b%3E0+\"\r
\n" ); document.write( "\n" ); document.write( "\"b%5E2%3E24b\"\r
\n" ); document.write( "\n" ); document.write( "\"b%3E24\"\r
\n" ); document.write( "\n" ); document.write( "solution is \"b%3E24\"\r
\n" ); document.write( "\n" ); document.write( "let have first one greater then\"24\":\"+b=25\"\r
\n" ); document.write( "\n" ); document.write( "\"highlight%28x%5E2+%2B+25x+%2B+6%2A25+=+0%29\" ...only has integer roots\r
\n" ); document.write( "\n" ); document.write( "proof:\r
\n" ); document.write( "\n" ); document.write( "\"x%5E2+%2B+25x+%2B+150+=+0\"\r
\n" ); document.write( "\n" ); document.write( "\"x%5E2+%2B+15x+%2B10x%2B+150+=+0\"\r
\n" ); document.write( "\n" ); document.write( "\"%28x%5E2+%2B+15x%29+%2B%2810x%2B+150+%29=+0\"\r
\n" ); document.write( "\n" ); document.write( "\"x%28x+%2B+15%29+%2B10%28x%2B+15+%29=+0\"\r
\n" ); document.write( "\n" ); document.write( "\"%28x%2B10%29+%28x%2B15%29+=+0\"\r
\n" ); document.write( "\n" ); document.write( "\"x+=+-15\" and \"x=-10\" ->solutions are integer roots\r
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\n" ); document.write( "\n" ); document.write( "\"+graph%28+600%2C+600%2C+-20%2C+5%2C+-10%2C+170%2C+x%5E2+%2B+25x+%2B+150%29+\"\r
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