(2y+9)(1+y)=0

Solution for (2y+9)(1+y)=0 equation:

Simplifying
(2y + 9)(1 + y) = 0

Reorder the terms:
(9 + 2y)(1 + y) = 0

Multiply (9 + 2y) * (1 + y)
(9(1 + y) + 2y * (1 + y)) = 0
((1 * 9 + y * 9) + 2y * (1 + y)) = 0
((9 + 9y) + 2y * (1 + y)) = 0
(9 + 9y + (1 * 2y + y * 2y)) = 0
(9 + 9y + (2y + 2y2)) = 0

Combine like terms: 9y + 2y = 11y
(9 + 11y + 2y2) = 0

Solving
9 + 11y + 2y2 = 0

Solving for variable 'y'.

Factor a trinomial.
(9 + 2y)(1 + y) = 0

Subproblem 1
Set the factor '(9 + 2y)' equal to zero and attempt to solve:

Simplifying
9 + 2y = 0

Solving
9 + 2y = 0

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

Add '-9' to each side of the equation.
9 + -9 + 2y = 0 + -9

Combine like terms: 9 + -9 = 0
0 + 2y = 0 + -9
2y = 0 + -9

Combine like terms: 0 + -9 = -9
2y = -9

Divide each side by '2'.
y = -4.5

Simplifying
y = -4.5
Subproblem 2
Set the factor '(1 + y)' equal to zero and attempt to solve:

Simplifying
1 + y = 0

Solving
1 + y = 0

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

Add '-1' to each side of the equation.
1 + -1 + y = 0 + -1

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

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

Simplifying
y = -1
Solution
y = {-4.5, -1}