document.write( "Question 1127572: Write the equation of a parabola with x-intercepts at (3, 0) and (9, 0) that passes through the point (10,-7)
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Algebra.Com's Answer #743994 by josmiceli(19441)\"\" \"About 
You can put this solution on YOUR website!
The general formula is:
\n" ); document.write( "\"+y+=+a%2Ax%5E2+%2B+b%2Ax+%2B+c+\"
\n" ); document.write( "( 3,0 )
\n" ); document.write( "( 9,0 )
\n" ); document.write( "( 10,-7 )
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\n" ); document.write( "( 3,0 )
\n" ); document.write( "\"+0+=+a%2A3%5E2+%2B+b%2A3+%2B+c+\"
\n" ); document.write( "(1) \"+9a+%2B+3b+%2B+c+=+0+\"
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\n" ); document.write( "(9,0)
\n" ); document.write( "\"+0+=+a%2A9%5E2+%2B+b%2A9+%2B+c+\"
\n" ); document.write( "(2) \"+81a+%2B+9b+%2B+c+=+0+\"
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\n" ); document.write( "( 10,-7 )
\n" ); document.write( "\"+-7+=+a%2A10%5E2+%2B+b%2A10+%2B+c+\"
\n" ); document.write( "(3) \"+100a+%2B+10b+%2B+c+%2B+7+=+0+\"
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\n" ); document.write( "Multiply both sides of (1) by \"+3+\"
\n" ); document.write( "and subtract (1) from (2)
\n" ); document.write( "\"+54a+-+3c+=+0+\"
\n" ); document.write( "\"+c+=+18a+\"
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\n" ); document.write( "Plug this result into (3)
\n" ); document.write( "(3) \"+100a+%2B+10b+%2B+18a+%2B+7+=+0+\"
\n" ); document.write( "(3) \"+118a+=+-10b+-+7+\"
\n" ); document.write( "(3) \"+10b+=+-118a+-+7+\"
\n" ); document.write( "(3) \"+b+=+%281%2F10%29%2A%28+-118a+-+7+%29+\"
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\n" ); document.write( "You can plug c and b back into (1) and
\n" ); document.write( "find a
\n" ); document.write( "Will let you finish\r
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