SOLUTION: x^2 + 8x - 5 = 0 Solve this quadratic equation using the quadratic formula.

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Question 668935: x^2 + 8x - 5 = 0
Solve this quadratic equation using the quadratic formula.
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
x+=+%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F%282a%29

x+=+%28-%288%29%2B-sqrt%28%288%29%5E2-4%281%29%28-5%29%29%29%2F%282%281%29%29

x+=+%28-8%2B-sqrt%2864-%28-20%29%29%29%2F%282%29

x+=+%28-8%2B-sqrt%2864%2B20%29%29%2F%282%29

x+=+%28-8%2B-sqrt%2884%29%29%2F2

x+=+%28-8%2Bsqrt%2884%29%29%2F2 or x+=+%28-8-sqrt%2884%29%29%2F2

x+=+%28-8%2B2%2Asqrt%2821%29%29%2F2 or x+=+%28-8-2%2Asqrt%2821%29%29%2F2

x+=+-4%2Bsqrt%2821%29 or x+=+-4-sqrt%2821%29

x+=+0.58257569495584 or x+=+-8.58257569495584

x+=+0.583 or x+=+-8.583



So the exact solutions are x+=+-4%2Bsqrt%2821%29 or x+=+-4-sqrt%2821%29

and the approximate solutions (to 3 decimal places) are x+=+0.583 or x+=+-8.583