a^2+4a=-16

Solution for a^2+4a=-16 equation:

Simplifying
a2 + 4a = -16

Reorder the terms:
4a + a2 = -16

Solving
4a + a2 = -16

Solving for variable 'a'.

Reorder the terms:
16 + 4a + a2 = -16 + 16

Combine like terms: -16 + 16 = 0
16 + 4a + a2 = 0

Begin completing the square.

Move the constant term to the right:

Add '-16' to each side of the equation.
16 + 4a + -16 + a2 = 0 + -16

Reorder the terms:
16 + -16 + 4a + a2 = 0 + -16

Combine like terms: 16 + -16 = 0
0 + 4a + a2 = 0 + -16
4a + a2 = 0 + -16

Combine like terms: 0 + -16 = -16
4a + a2 = -16

The a term is 4a.  Take half its coefficient (2).
Square it (4) and add it to both sides.

Add '4' to each side of the equation.
4a + 4 + a2 = -16 + 4

Reorder the terms:
4 + 4a + a2 = -16 + 4

Combine like terms: -16 + 4 = -12
4 + 4a + a2 = -12

Factor a perfect square on the left side:
(a + 2)(a + 2) = -12

Can't calculate square root of the right side.

The solution to this equation could not be determined.