4x^2+13x+168=0

Solution for 4x^2+13x+168=0 equation:

Simplifying
4x2 + 13x + 168 = 0

Reorder the terms:
168 + 13x + 4x2 = 0

Solving
168 + 13x + 4x2 = 0

Solving for variable 'x'.

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

Divide each side by '4'.
42 + 3.25x + x2 = 0

Move the constant term to the right:

Add '-42' to each side of the equation.
42 + 3.25x + -42 + x2 = 0 + -42

Reorder the terms:
42 + -42 + 3.25x + x2 = 0 + -42

Combine like terms: 42 + -42 = 0
0 + 3.25x + x2 = 0 + -42
3.25x + x2 = 0 + -42

Combine like terms: 0 + -42 = -42
3.25x + x2 = -42

The x term is 3.25x.  Take half its coefficient (1.625).
Square it (2.640625) and add it to both sides.

Add '2.640625' to each side of the equation.
3.25x + 2.640625 + x2 = -42 + 2.640625

Reorder the terms:
2.640625 + 3.25x + x2 = -42 + 2.640625

Combine like terms: -42 + 2.640625 = -39.359375
2.640625 + 3.25x + x2 = -39.359375

Factor a perfect square on the left side:
(x + 1.625)(x + 1.625) = -39.359375

Can't calculate square root of the right side.

The solution to this equation could not be determined.