SOLUTION: use quadratic formula exact solution only a^2-7a-10=0

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Question 878956: use quadratic formula exact solution only
a^2-7a-10=0
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
I'm going to refer to a%5E2-7a-10=0 as x%5E2-7x-10=0

x%5E2-7x-10=0 is in the form ax%5E2%2Bbx%2Bc=0 where a+=+1, b+=+-7, c+=+-10

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Use the quadratic formula to solve for x

x+=+%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F%282a%29

x+=+%28-%28-7%29%2B-sqrt%28%28-7%29%5E2-4%281%29%28-10%29%29%29%2F%282%281%29%29 Plug in a+=+1, b+=+-7, c+=+-10

x+=+%287%2B-sqrt%2849-%28-40%29%29%29%2F%282%29

x+=+%287%2B-sqrt%2849%2B40%29%29%2F%282%29

x+=+%287%2B-sqrt%2889%29%29%2F2

x+=+%287%2Bsqrt%2889%29%29%2F2 or x+=+%287-sqrt%2889%29%29%2F2