2x^2-x-1=-5

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Solution for 2x^2-x-1=-5 equation:


Simplifying
2x2 + -1x + -1 = -5

Reorder the terms:
-1 + -1x + 2x2 = -5

Solving
-1 + -1x + 2x2 = -5

Solving for variable 'x'.

Reorder the terms:
-1 + 5 + -1x + 2x2 = -5 + 5

Combine like terms: -1 + 5 = 4
4 + -1x + 2x2 = -5 + 5

Combine like terms: -5 + 5 = 0
4 + -1x + 2x2 = 0

Begin completing the square.  Divide all terms by
2 the coefficient of the squared term: 

Divide each side by '2'.
2 + -0.5x + x2 = 0

Move the constant term to the right:

Add '-2' to each side of the equation.
2 + -0.5x + -2 + x2 = 0 + -2

Reorder the terms:
2 + -2 + -0.5x + x2 = 0 + -2

Combine like terms: 2 + -2 = 0
0 + -0.5x + x2 = 0 + -2
-0.5x + x2 = 0 + -2

Combine like terms: 0 + -2 = -2
-0.5x + x2 = -2

The x term is -0.5x.  Take half its coefficient (-0.25).
Square it (0.0625) and add it to both sides.

Add '0.0625' to each side of the equation.
-0.5x + 0.0625 + x2 = -2 + 0.0625

Reorder the terms:
0.0625 + -0.5x + x2 = -2 + 0.0625

Combine like terms: -2 + 0.0625 = -1.9375
0.0625 + -0.5x + x2 = -1.9375

Factor a perfect square on the left side:
(x + -0.25)(x + -0.25) = -1.9375

Can't calculate square root of the right side.

The solution to this equation could not be determined.

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