document.write( "Question 689806: Find an equation in standard form of the parabola passing through the following points (-1,1) (0,5) (2,7)\r
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Algebra.Com's Answer #426065 by lwsshak3(11628)\"\" \"About 
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Find an equation in standard form of the parabola passing through the following points (-1,1) (0,5) (2,7)
\n" ); document.write( "y=Ax^2+Bx+C
\n" ); document.write( "(1) 1=A-B+C (-1,1)
\n" ); document.write( "(2) 5=C (0,5)
\n" ); document.write( "(3) 7=4A+2B+C (2,7)
\n" ); document.write( "..
\n" ); document.write( "1=A-B+5
\n" ); document.write( "7=4A+2B+5
\n" ); document.write( "2=2A-2B+10
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\n" ); document.write( "9=6A+15
\n" ); document.write( "6A=-6
\n" ); document.write( "A=-1
\n" ); document.write( "..
\n" ); document.write( "B=A+5-1=3
\n" ); document.write( "Equation:
\n" ); document.write( "y=Ax^2+Bx+C
\n" ); document.write( "y=-x^2+3x+5
\n" ); document.write( "complete the square
\n" ); document.write( "y=-(x^2-3x+9/4)+9/4+5
\n" ); document.write( "y=-(x-3/2)^2+29/4
\n" ); document.write( "This is an equation of a parabola that opens downwards with vertex at(3/2,29/4)\r
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