document.write( "Question 1150290: Find the quadratic Equation that fits the following set of Data points. (5,162),(4,110),(1,14) \n" ); document.write( "
Algebra.Com's Answer #771674 by ankor@dixie-net.com(22740)\"\" \"About 
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Find the quadratic Equation that fits the following set of Data points. (5,162),(4,110),(1,14)
\n" ); document.write( ":
\n" ); document.write( "using the form: ax^2 + bx + c = y
\n" ); document.write( "x=5, y=162
\n" ); document.write( "25a + 5b + c = 162
\n" ); document.write( ":
\n" ); document.write( "x=4; y=110
\n" ); document.write( "16a + 4b + c = 110
\n" ); document.write( ":
\n" ); document.write( "x=1, y=14
\n" ); document.write( "a + b + c = 14
\n" ); document.write( ":
\n" ); document.write( "use elimination on 1st two equations
\n" ); document.write( "25a + 5b + c = 162
\n" ); document.write( "16a + 4b + c = 110
\n" ); document.write( "--------------------subtraction eliminates c
\n" ); document.write( "9a + b = 52
\n" ); document.write( ":
\n" ); document.write( "use elimination on last two equations
\n" ); document.write( "16a + 4b + c = 110
\n" ); document.write( " a + b + c = 14
\n" ); document.write( "--------------------subtraction eliminates c
\n" ); document.write( "15a + 3b = 96
\n" ); document.write( "simplify divide by 3
\n" ); document.write( "5a + b = 32
\n" ); document.write( ":
\n" ); document.write( "use elimination on the resulting two equations
\n" ); document.write( "9a + b = 52
\n" ); document.write( "5a + b = 32
\n" ); document.write( "--------------subtraction eliminates b
\n" ); document.write( "4a = 20
\n" ); document.write( "a = 5
\n" ); document.write( ":
\n" ); document.write( "substituting 5 for a in the 1st two equations
\n" ); document.write( "125 + 5b + c = 162
\n" ); document.write( "5b + c = 162 - 125
\n" ); document.write( "5b + c = 37
\n" ); document.write( "and
\n" ); document.write( "80 + 4b + c = 110
\n" ); document.write( "4b + c = 110 - 80
\n" ); document.write( "4b + c = 30
\n" ); document.write( ":
\n" ); document.write( "using elimination in these two equations
\n" ); document.write( "5b + c = 37
\n" ); document.write( "4b + c = 30
\n" ); document.write( "-------------subtraction eliminates c
\n" ); document.write( "b = 7
\n" ); document.write( ":
\n" ); document.write( "use the last original equation to find c
\n" ); document.write( "5 + 7 + c = 14
\n" ); document.write( "c = 14 - 12
\n" ); document.write( "c = 2
\n" ); document.write( ":
\n" ); document.write( "The equation for the given points:
\n" ); document.write( "y = 5x^2 + 7x + 2
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\n" ); document.write( "I'll let you confirm this is true
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