r^2+6r+72=0

Solution for r^2+6r+72=0 equation:

Simplifying
r2 + 6r + 72 = 0

Reorder the terms:
72 + 6r + r2 = 0

Solving
72 + 6r + r2 = 0

Solving for variable 'r'.

Begin completing the square.

Move the constant term to the right:

Add '-72' to each side of the equation.
72 + 6r + -72 + r2 = 0 + -72

Reorder the terms:
72 + -72 + 6r + r2 = 0 + -72

Combine like terms: 72 + -72 = 0
0 + 6r + r2 = 0 + -72
6r + r2 = 0 + -72

Combine like terms: 0 + -72 = -72
6r + r2 = -72

The r term is 6r.  Take half its coefficient (3).
Square it (9) and add it to both sides.

Add '9' to each side of the equation.
6r + 9 + r2 = -72 + 9

Reorder the terms:
9 + 6r + r2 = -72 + 9

Combine like terms: -72 + 9 = -63
9 + 6r + r2 = -63

Factor a perfect square on the left side:
(r + 3)(r + 3) = -63

Can't calculate square root of the right side.

The solution to this equation could not be determined.