SOLUTION: Find a quadratic equation of the form ax^2+bx+c=0 whose solutons are x=4+ or - square root of 11

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Question 132855: Find a quadratic equation of the form ax^2+bx+c=0 whose solutons are x=4+ or - square root of 11
Answer by Edwin McCravy(20055) About Me  (Show Source):
You can put this solution on YOUR website!
Find a quadratic equation of the form ax^2+bx+c=0 whose solutons are
x=4%2B-sqrt%2811%29


Formula:

A quadratic equation of the form ax%5E2%2Bbx%2Bc=0 which has solutions M and N
is x%5E2-%28M%2BN%29x%2BMN=0

Therefore:

M+=+4%2Bsqrt%2811%29, N+=+4-sqrt%2811%29

M%2BN=4%2Bsqrt%2811%29%2B4-sqrt%2811%29 = 8

MN=%284%2Bsqrt%2811%29%29%284-sqrt%2811%29%29 = 16-4sqrt%2811%29%2B4sqrt%2811%29-sqrt%2811%29sqrt%2811%29 = 16-cross%284sqrt%2811%29%29%2Bcross%284sqrt%2811%29%29-11 = 16-11 = 5.

So substituting in 

x%5E2-%28M%2BN%29x%2BMN=0 

gives the equation

 x%5E2-8x%2B5=0

Edwin