(r+4)(r+4)=-15

Solution for (r+4)(r+4)=-15 equation:

Simplifying
(r + 4)(r + 4) = -15

Reorder the terms:
(4 + r)(r + 4) = -15

Reorder the terms:
(4 + r)(4 + r) = -15

Multiply (4 + r) * (4 + r)
(4(4 + r) + r(4 + r)) = -15
((4 * 4 + r * 4) + r(4 + r)) = -15
((16 + 4r) + r(4 + r)) = -15
(16 + 4r + (4 * r + r * r)) = -15
(16 + 4r + (4r + r2)) = -15

Combine like terms: 4r + 4r = 8r
(16 + 8r + r2) = -15

Solving
16 + 8r + r2 = -15

Solving for variable 'r'.

Reorder the terms:
16 + 15 + 8r + r2 = -15 + 15

Combine like terms: 16 + 15 = 31
31 + 8r + r2 = -15 + 15

Combine like terms: -15 + 15 = 0
31 + 8r + r2 = 0

Begin completing the square.

Move the constant term to the right:

Add '-31' to each side of the equation.
31 + 8r + -31 + r2 = 0 + -31

Reorder the terms:
31 + -31 + 8r + r2 = 0 + -31

Combine like terms: 31 + -31 = 0
0 + 8r + r2 = 0 + -31
8r + r2 = 0 + -31

Combine like terms: 0 + -31 = -31
8r + r2 = -31

The r term is 8r.  Take half its coefficient (4).
Square it (16) and add it to both sides.

Add '16' to each side of the equation.
8r + 16 + r2 = -31 + 16

Reorder the terms:
16 + 8r + r2 = -31 + 16

Combine like terms: -31 + 16 = -15
16 + 8r + r2 = -15

Factor a perfect square on the left side:
(r + 4)(r + 4) = -15

Can't calculate square root of the right side.

The solution to this equation could not be determined.