f(f+9)=0

Solution for f(f+9)=0 equation:

Simplifying
f(f + 9) = 0

Reorder the terms:
f(9 + f) = 0
(9 * f + f * f) = 0
(9f + f2) = 0

Solving
9f + f2 = 0

Solving for variable 'f'.

Factor out the Greatest Common Factor (GCF), 'f'.
f(9 + f) = 0

Subproblem 1
Set the factor 'f' equal to zero and attempt to solve:

Simplifying
f = 0

Solving
f = 0

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

Simplifying
f = 0
Subproblem 2
Set the factor '(9 + f)' equal to zero and attempt to solve:

Simplifying
9 + f = 0

Solving
9 + f = 0

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

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

Combine like terms: 9 + -9 = 0
0 + f = 0 + -9
f = 0 + -9

Combine like terms: 0 + -9 = -9
f = -9

Simplifying
f = -9
Solution
f = {0, -9}