5x^2+5x+8=0

Solution for 5x^2+5x+8=0 equation:

Simplifying
5x2 + 5x + 8 = 0

Reorder the terms:
8 + 5x + 5x2 = 0

Solving
8 + 5x + 5x2 = 0

Solving for variable 'x'.

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

Divide each side by '5'.
1.6 + x + x2 = 0

Move the constant term to the right:

Add '-1.6' to each side of the equation.
1.6 + x + -1.6 + x2 = 0 + -1.6

Reorder the terms:
1.6 + -1.6 + x + x2 = 0 + -1.6

Combine like terms: 1.6 + -1.6 = 0.0
0.0 + x + x2 = 0 + -1.6
x + x2 = 0 + -1.6

Combine like terms: 0 + -1.6 = -1.6
x + x2 = -1.6

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

Add '0.25' to each side of the equation.
 + 0.25 + x2 = -1.6 + 0.25

Combine like terms:  + 0.25 = 1.25
1.25 + x2 = -1.6 + 0.25

Combine like terms: -1.6 + 0.25 = -1.35
1.25 + x2 = -1.35

Factor a perfect square on the left side:
(x + 0.5)(x + 0.5) = -1.35

Can't calculate square root of the right side.

The solution to this equation could not be determined.