10r^2+19r+16=0

Solution for 10r^2+19r+16=0 equation:

Simplifying
10r2 + 19r + 16 = 0

Reorder the terms:
16 + 19r + 10r2 = 0

Solving
16 + 19r + 10r2 = 0

Solving for variable 'r'.

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

Divide each side by '10'.
1.6 + 1.9r + r2 = 0

Move the constant term to the right:

Add '-1.6' to each side of the equation.
1.6 + 1.9r + -1.6 + r2 = 0 + -1.6

Reorder the terms:
1.6 + -1.6 + 1.9r + r2 = 0 + -1.6

Combine like terms: 1.6 + -1.6 = 0.0
0.0 + 1.9r + r2 = 0 + -1.6
1.9r + r2 = 0 + -1.6

Combine like terms: 0 + -1.6 = -1.6
1.9r + r2 = -1.6

The r term is 1.9r.  Take half its coefficient (0.95).
Square it (0.9025) and add it to both sides.

Add '0.9025' to each side of the equation.
1.9r + 0.9025 + r2 = -1.6 + 0.9025

Reorder the terms:
0.9025 + 1.9r + r2 = -1.6 + 0.9025

Combine like terms: -1.6 + 0.9025 = -0.6975
0.9025 + 1.9r + r2 = -0.6975

Factor a perfect square on the left side:
(r + 0.95)(r + 0.95) = -0.6975

Can't calculate square root of the right side.

The solution to this equation could not be determined.