r^2+18r+73=-9

Solution for r^2+18r+73=-9 equation:

Simplifying
r2 + 18r + 73 = -9

Reorder the terms:
73 + 18r + r2 = -9

Solving
73 + 18r + r2 = -9

Solving for variable 'r'.

Reorder the terms:
73 + 9 + 18r + r2 = -9 + 9

Combine like terms: 73 + 9 = 82
82 + 18r + r2 = -9 + 9

Combine like terms: -9 + 9 = 0
82 + 18r + r2 = 0

Begin completing the square.

Move the constant term to the right:

Add '-82' to each side of the equation.
82 + 18r + -82 + r2 = 0 + -82

Reorder the terms:
82 + -82 + 18r + r2 = 0 + -82

Combine like terms: 82 + -82 = 0
0 + 18r + r2 = 0 + -82
18r + r2 = 0 + -82

Combine like terms: 0 + -82 = -82
18r + r2 = -82

The r term is 18r.  Take half its coefficient (9).
Square it (81) and add it to both sides.

Add '81' to each side of the equation.
18r + 81 + r2 = -82 + 81

Reorder the terms:
81 + 18r + r2 = -82 + 81

Combine like terms: -82 + 81 = -1
81 + 18r + r2 = -1

Factor a perfect square on the left side:
(r + 9)(r + 9) = -1

Can't calculate square root of the right side.

The solution to this equation could not be determined.