3.4c(5c+1)=-12.5

Solution for 3.4c(5c+1)=-12.5 equation:

Simplifying
3.4c(5c + 1) = -12.5

Reorder the terms:
3.4c(1 + 5c) = -12.5
(1 * 3.4c + 5c * 3.4c) = -12.5
(3.4c + 17c2) = -12.5

Solving
3.4c + 17c2 = -12.5

Solving for variable 'c'.

Reorder the terms:
12.5 + 3.4c + 17c2 = -12.5 + 12.5

Combine like terms: -12.5 + 12.5 = 0.0
12.5 + 3.4c + 17c2 = 0.0

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

Divide each side by '17'.
0.7352941176 + 0.2c + c2 = 0.0

Move the constant term to the right:

Add '-0.7352941176' to each side of the equation.
0.7352941176 + 0.2c + -0.7352941176 + c2 = 0.0 + -0.7352941176

Reorder the terms:
0.7352941176 + -0.7352941176 + 0.2c + c2 = 0.0 + -0.7352941176

Combine like terms: 0.7352941176 + -0.7352941176 = 0.0000000000
0.0000000000 + 0.2c + c2 = 0.0 + -0.7352941176
0.2c + c2 = 0.0 + -0.7352941176

Combine like terms: 0.0 + -0.7352941176 = -0.7352941176
0.2c + c2 = -0.7352941176

The c term is 0.2c.  Take half its coefficient (0.1).
Square it (0.01) and add it to both sides.

Add '0.01' to each side of the equation.
0.2c + 0.01 + c2 = -0.7352941176 + 0.01

Reorder the terms:
0.01 + 0.2c + c2 = -0.7352941176 + 0.01

Combine like terms: -0.7352941176 + 0.01 = -0.7252941176
0.01 + 0.2c + c2 = -0.7252941176

Factor a perfect square on the left side:
(c + 0.1)(c + 0.1) = -0.7252941176

Can't calculate square root of the right side.

The solution to this equation could not be determined.