Question 1052699:  Find a quadratic model for the set of values: (-2, -20), (0, -4), (4, -20).  Show your work.  
 Answer by stanbon(75887)      (Show Source): 
You can  put this solution on YOUR website!  Find a quadratic model for the set of values: 
Form:::::::::: ax^2 + bx + c = y 
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(-2, -20):::::a(4) - 2b + c = -20 
(0, -4)::::::: 0   +  0 + c = -4 
(4, -20):::::: a(16) +4b + c = -20 
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Note:: c = -4 
4a - 2b -4 = -20 
16a + 4b -4 = -20 
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4a - 2b = -16 
16a + 4b = -16 
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Modify for elimination:: 
8a - 4b = -32 
16a + 4b = -16 
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24a = -48 
a = -2 
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Solve for "b":: 
4a - 2b = -16 
4(-2) - 2b = -16 
-8 - 2b = -16 
2b = 8 
b = 4 
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Cheers, 
Stan H. 
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