0.9z^2=1.2z-0.4

Solution for 0.9z^2=1.2z-0.4 equation:

Simplifying
0.9z2 = 1.2z + -0.4

Reorder the terms:
0.9z2 = -0.4 + 1.2z

Solving
0.9z2 = -0.4 + 1.2z

Solving for variable 'z'.

Reorder the terms:
0.4 + -1.2z + 0.9z2 = -0.4 + 1.2z + 0.4 + -1.2z

Reorder the terms:
0.4 + -1.2z + 0.9z2 = -0.4 + 0.4 + 1.2z + -1.2z

Combine like terms: -0.4 + 0.4 = 0.0
0.4 + -1.2z + 0.9z2 = 0.0 + 1.2z + -1.2z
0.4 + -1.2z + 0.9z2 = 1.2z + -1.2z

Combine like terms: 1.2z + -1.2z = 0.0
0.4 + -1.2z + 0.9z2 = 0.0

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

Divide each side by '0.9'.
0.4444444444 + -1.333333333z + z2 = 0

Move the constant term to the right:

Add '-0.4444444444' to each side of the equation.
0.4444444444 + -1.333333333z + -0.4444444444 + z2 = 0 + -0.4444444444

Reorder the terms:
0.4444444444 + -0.4444444444 + -1.333333333z + z2 = 0 + -0.4444444444

Combine like terms: 0.4444444444 + -0.4444444444 = 0.0000000000
0.0000000000 + -1.333333333z + z2 = 0 + -0.4444444444
-1.333333333z + z2 = 0 + -0.4444444444

Combine like terms: 0 + -0.4444444444 = -0.4444444444
-1.333333333z + z2 = -0.4444444444

The z term is -1.333333333z.  Take half its coefficient (-0.6666666665).
Square it (0.4444444442) and add it to both sides.

Add '0.4444444442' to each side of the equation.
-1.333333333z + 0.4444444442 + z2 = -0.4444444444 + 0.4444444442

Reorder the terms:
0.4444444442 + -1.333333333z + z2 = -0.4444444444 + 0.4444444442

Combine like terms: -0.4444444444 + 0.4444444442 = -0.0000000002
0.4444444442 + -1.333333333z + z2 = -0.0000000002

Factor a perfect square on the left side:
(z + -0.6666666665)(z + -0.6666666665) = -0.0000000002

Can't calculate square root of the right side.

The solution to this equation could not be determined.