-2y-4=y(y-1)

Solution for -2y-4=y(y-1) equation:

Simplifying
-2y + -4 = y(y + -1)

Reorder the terms:
-4 + -2y = y(y + -1)

Reorder the terms:
-4 + -2y = y(-1 + y)
-4 + -2y = (-1 * y + y * y)
-4 + -2y = (-1y + y2)

Solving
-4 + -2y = -1y + y2

Solving for variable 'y'.

Combine like terms: -2y + y = -1y
-4 + -1y + -1y2 = -1y + y2 + y + -1y2

Reorder the terms:
-4 + -1y + -1y2 = -1y + y + y2 + -1y2

Combine like terms: -1y + y = 0
-4 + -1y + -1y2 = 0 + y2 + -1y2
-4 + -1y + -1y2 = y2 + -1y2

Combine like terms: y2 + -1y2 = 0
-4 + -1y + -1y2 = 0

Factor out the Greatest Common Factor (GCF), '-1'.
-1(4 + y + y2) = 0

Ignore the factor -1.
Subproblem 1
Set the factor '(4 + y + y2)' equal to zero and attempt to solve:

Simplifying
4 + y + y2 = 0

Solving
4 + y + y2 = 0

Begin completing the square.

Move the constant term to the right:

Add '-4' to each side of the equation.
4 + y + -4 + y2 = 0 + -4

Reorder the terms:
4 + -4 + y + y2 = 0 + -4

Combine like terms: 4 + -4 = 0
0 + y + y2 = 0 + -4
y + y2 = 0 + -4

Combine like terms: 0 + -4 = -4
y + y2 = -4

The y term is y.  Take half its coefficient (0.5).
Square it (0.25) and add it to both sides.

Add '0.25' to each side of the equation.
y + 0.25 + y2 = -4 + 0.25

Reorder the terms:
0.25 + y + y2 = -4 + 0.25

Combine like terms: -4 + 0.25 = -3.75
0.25 + y + y2 = -3.75

Factor a perfect square on the left side:
(y + 0.5)(y + 0.5) = -3.75

Can't calculate square root of the right side.

The solution to this equation could not be determined.

This subproblem is being ignored because a solution could not be determined.

The solution to this equation could not be determined.