2(u-3)(-u-9)=0

Solution for 2(u-3)(-u-9)=0 equation:

Simplifying
2(u + -3)(-1u + -9) = 0

Reorder the terms:
2(-3 + u)(-1u + -9) = 0

Reorder the terms:
2(-3 + u)(-9 + -1u) = 0

Multiply (-3 + u) * (-9 + -1u)
2(-3(-9 + -1u) + u(-9 + -1u)) = 0
2((-9 * -3 + -1u * -3) + u(-9 + -1u)) = 0
2((27 + 3u) + u(-9 + -1u)) = 0
2(27 + 3u + (-9 * u + -1u * u)) = 0
2(27 + 3u + (-9u + -1u2)) = 0

Combine like terms: 3u + -9u = -6u
2(27 + -6u + -1u2) = 0
(27 * 2 + -6u * 2 + -1u2 * 2) = 0
(54 + -12u + -2u2) = 0

Solving
54 + -12u + -2u2 = 0

Solving for variable 'u'.

Factor out the Greatest Common Factor (GCF), '2'.
2(27 + -6u + -1u2) = 0

Factor a trinomial.
2((3 + -1u)(9 + u)) = 0

Ignore the factor 2.
Subproblem 1
Set the factor '(3 + -1u)' equal to zero and attempt to solve:

Simplifying
3 + -1u = 0

Solving
3 + -1u = 0

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

Add '-3' to each side of the equation.
3 + -3 + -1u = 0 + -3

Combine like terms: 3 + -3 = 0
0 + -1u = 0 + -3
-1u = 0 + -3

Combine like terms: 0 + -3 = -3
-1u = -3

Divide each side by '-1'.
u = 3

Simplifying
u = 3
Subproblem 2
Set the factor '(9 + u)' equal to zero and attempt to solve:

Simplifying
9 + u = 0

Solving
9 + u = 0

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

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

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

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

Simplifying
u = -9
Solution
u = {3, -9}