10r^2+3r+2=0

Solution for 10r^2+3r+2=0 equation:

Simplifying
10r2 + 3r + 2 = 0

Reorder the terms:
2 + 3r + 10r2 = 0

Solving
2 + 3r + 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'.
0.2 + 0.3r + r2 = 0

Move the constant term to the right:

Add '-0.2' to each side of the equation.
0.2 + 0.3r + -0.2 + r2 = 0 + -0.2

Reorder the terms:
0.2 + -0.2 + 0.3r + r2 = 0 + -0.2

Combine like terms: 0.2 + -0.2 = 0.0
0.0 + 0.3r + r2 = 0 + -0.2
0.3r + r2 = 0 + -0.2

Combine like terms: 0 + -0.2 = -0.2
0.3r + r2 = -0.2

The r term is 0.3r.  Take half its coefficient (0.15).
Square it (0.0225) and add it to both sides.

Add '0.0225' to each side of the equation.
0.3r + 0.0225 + r2 = -0.2 + 0.0225

Reorder the terms:
0.0225 + 0.3r + r2 = -0.2 + 0.0225

Combine like terms: -0.2 + 0.0225 = -0.1775
0.0225 + 0.3r + r2 = -0.1775

Factor a perfect square on the left side:
(r + 0.15)(r + 0.15) = -0.1775

Can't calculate square root of the right side.

The solution to this equation could not be determined.