SOLUTION: solve using Q. F. Formula x=-b+- sq b-4ac/2a 2x^2+x-1=0 the answer is 1/2,1 I'm new to these so please help....thanks!

Algebra ->  Expressions-with-variables -> SOLUTION: solve using Q. F. Formula x=-b+- sq b-4ac/2a 2x^2+x-1=0 the answer is 1/2,1 I'm new to these so please help....thanks!      Log On


   

Question 84685: solve using Q. F. Formula x=-b+- sq b-4ac/2a

2x^2+x-1=0 the answer is 1/2,1

I'm new to these so please help....thanks!
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Solve using the quadratic formula: x+=+%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F2a
2x%5E2%2Bx-1+=+0 Here, a = 2, b = 1, and c = -1 So, making the appropriate substitutions, we get:
x+=+%28-1%2B-sqrt%281%5E2-4%282%29%28-1%29%29%29%2F2%282%29 Now simplify this.
x+=+%28-1%2B-sqrt%281%2B8%29%29%2F4
x+=+%28-1%2B-sqrt%289%29%29%2F4
x+=+%28-1%2B3%29%2F4 or x+=+%28-1-3%29%2F4
x+=+1%2F2 or x+=+-1 Note the negative on the 1.