-9y^4(9y^2+3y-7)=

Solution for -9y^4(9y^2+3y-7)= equation:

Simplifying
-9y4(9y2 + 3y + -7) = 0

Reorder the terms:
-9y4(-7 + 3y + 9y2) = 0
(-7 * -9y4 + 3y * -9y4 + 9y2 * -9y4) = 0
(63y4 + -27y5 + -81y6) = 0

Solving
63y4 + -27y5 + -81y6 = 0

Solving for variable 'y'.

Factor out the Greatest Common Factor (GCF), '9y4'.
9y4(7 + -3y + -9y2) = 0

Ignore the factor 9.
Subproblem 1
Set the factor 'y4' equal to zero and attempt to solve:

Simplifying
y4 = 0

Solving
y4 = 0

Move all terms containing y to the left, all other terms to the right.

Simplifying
y4 = 0

The solution to this equation could not be determined.

This subproblem is being ignored because a solution could not be determined.
Subproblem 2
Set the factor '(7 + -3y + -9y2)' equal to zero and attempt to solve:

Simplifying
7 + -3y + -9y2 = 0

Solving
7 + -3y + -9y2 = 0

Begin completing the square.  Divide all terms by
-9 the coefficient of the squared term: 

Divide each side by '-9'.
-0.7777777778 + 0.3333333333y + y2 = 0

Move the constant term to the right:

Add '0.7777777778' to each side of the equation.
-0.7777777778 + 0.3333333333y + 0.7777777778 + y2 = 0 + 0.7777777778

Reorder the terms:
-0.7777777778 + 0.7777777778 + 0.3333333333y + y2 = 0 + 0.7777777778

Combine like terms: -0.7777777778 + 0.7777777778 = 0.0000000000
0.0000000000 + 0.3333333333y + y2 = 0 + 0.7777777778
0.3333333333y + y2 = 0 + 0.7777777778

Combine like terms: 0 + 0.7777777778 = 0.7777777778
0.3333333333y + y2 = 0.7777777778

The y term is 0.3333333333y.  Take half its coefficient (0.1666666667).
Square it (0.02777777779) and add it to both sides.

Add '0.02777777779' to each side of the equation.
0.3333333333y + 0.02777777779 + y2 = 0.7777777778 + 0.02777777779

Reorder the terms:
0.02777777779 + 0.3333333333y + y2 = 0.7777777778 + 0.02777777779

Combine like terms: 0.7777777778 + 0.02777777779 = 0.80555555559
0.02777777779 + 0.3333333333y + y2 = 0.80555555559

Factor a perfect square on the left side:
(y + 0.1666666667)(y + 0.1666666667) = 0.80555555559

Calculate the square root of the right side: 0.897527468

Break this problem into two subproblems by setting 
(y + 0.1666666667) equal to 0.897527468 and -0.897527468.

Subproblem 1
y + 0.1666666667 = 0.897527468

Simplifying
y + 0.1666666667 = 0.897527468

Reorder the terms:
0.1666666667 + y = 0.897527468

Solving
0.1666666667 + y = 0.897527468

Solving for variable 'y'.

Move all terms containing y to the left, all other terms to the right.

Add '-0.1666666667' to each side of the equation.
0.1666666667 + -0.1666666667 + y = 0.897527468 + -0.1666666667

Combine like terms: 0.1666666667 + -0.1666666667 = 0.0000000000
0.0000000000 + y = 0.897527468 + -0.1666666667
y = 0.897527468 + -0.1666666667

Combine like terms: 0.897527468 + -0.1666666667 = 0.7308608013
y = 0.7308608013

Simplifying
y = 0.7308608013

Subproblem 2
y + 0.1666666667 = -0.897527468

Simplifying
y + 0.1666666667 = -0.897527468

Reorder the terms:
0.1666666667 + y = -0.897527468

Solving
0.1666666667 + y = -0.897527468

Solving for variable 'y'.

Move all terms containing y to the left, all other terms to the right.

Add '-0.1666666667' to each side of the equation.
0.1666666667 + -0.1666666667 + y = -0.897527468 + -0.1666666667

Combine like terms: 0.1666666667 + -0.1666666667 = 0.0000000000
0.0000000000 + y = -0.897527468 + -0.1666666667
y = -0.897527468 + -0.1666666667

Combine like terms: -0.897527468 + -0.1666666667 = -1.0641941347
y = -1.0641941347

Simplifying
y = -1.0641941347

Solution
The solution to the problem is based on the solutions
from the subproblems.
y = {0.7308608013, -1.0641941347}
Solution
y = {0.7308608013, -1.0641941347}