2x^2+20x+80=9

Solution for 2x^2+20x+80=9 equation:

Simplifying
2x2 + 20x + 80 = 9

Reorder the terms:
80 + 20x + 2x2 = 9

Solving
80 + 20x + 2x2 = 9

Solving for variable 'x'.

Reorder the terms:
80 + -9 + 20x + 2x2 = 9 + -9

Combine like terms: 80 + -9 = 71
71 + 20x + 2x2 = 9 + -9

Combine like terms: 9 + -9 = 0
71 + 20x + 2x2 = 0

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

Divide each side by '2'.
35.5 + 10x + x2 = 0

Move the constant term to the right:

Add '-35.5' to each side of the equation.
35.5 + 10x + -35.5 + x2 = 0 + -35.5

Reorder the terms:
35.5 + -35.5 + 10x + x2 = 0 + -35.5

Combine like terms: 35.5 + -35.5 = 0.0
0.0 + 10x + x2 = 0 + -35.5
10x + x2 = 0 + -35.5

Combine like terms: 0 + -35.5 = -35.5
10x + x2 = -35.5

The x term is 10x.  Take half its coefficient (5).
Square it (25) and add it to both sides.

Add '25' to each side of the equation.
10x + 25 + x2 = -35.5 + 25

Reorder the terms:
25 + 10x + x2 = -35.5 + 25

Combine like terms: -35.5 + 25 = -10.5
25 + 10x + x2 = -10.5

Factor a perfect square on the left side:
(x + 5)(x + 5) = -10.5

Can't calculate square root of the right side.

The solution to this equation could not be determined.