SOLUTION: I am sorry if I picked the wrong type of question, I did not see one about completion of squares. I was wondering if you wouldnt mind checking the answer I got for the equation x^2

Algebra ->  Radicals -> SOLUTION: I am sorry if I picked the wrong type of question, I did not see one about completion of squares. I was wondering if you wouldnt mind checking the answer I got for the equation x^2      Log On


   

Question 41973: I am sorry if I picked the wrong type of question, I did not see one about completion of squares. I was wondering if you wouldnt mind checking the answer I got for the equation x^2-8x=25. What I calculated as a final answer was
4+ 3i and 4-3i.
Thank you for your time,
Kendall
Answer by psbhowmick(878) About Me  (Show Source):
You can put this solution on YOUR website!
Your answer is incorrect.

METHOD OF CHECKING:
Your equation: x%5E2-8x-25=0.
So sum of the roots = -%28-8%29%2F1 = 8
and product of the roots = -25%2F1 = -25

The sum and products of the roots you have obtained are 8 and 25 respectively.
So your answer is incorrect.



Use the quadratic formula: x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
Comparing with the standard quadratic equation ax%5E2%2Bbx%2Bc=0, here a = 1, b = -8, c = -25.
Hence, x+=+%28-%28-8%29+%2B-+sqrt%28+%28-8%29%5E2-4%2A1%2A%28-25%29+%29%29%2F%282%2A1%29+
or x+=+%288+%2B-+sqrt%28164%29%29%2F2+
or x+=+%288+%2B-+2%2Asqrt%2841%29%29%2F2+
or x+=+4+%2B-+sqrt%2841%29