(u+3)(u-4)=

Solution for (u+3)(u-4)= equation:

Simplifying
(u + 3)(u + -4) = 0

Reorder the terms:
(3 + u)(u + -4) = 0

Reorder the terms:
(3 + u)(-4 + u) = 0

Multiply (3 + u) * (-4 + u)
(3(-4 + u) + u(-4 + u)) = 0
((-4 * 3 + u * 3) + u(-4 + u)) = 0
((-12 + 3u) + u(-4 + u)) = 0
(-12 + 3u + (-4 * u + u * u)) = 0
(-12 + 3u + (-4u + u2)) = 0

Combine like terms: 3u + -4u = -1u
(-12 + -1u + u2) = 0

Solving
-12 + -1u + u2 = 0

Solving for variable 'u'.

Factor a trinomial.
(-3 + -1u)(4 + -1u) = 0

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 '(4 + -1u)' equal to zero and attempt to solve:

Simplifying
4 + -1u = 0

Solving
4 + -1u = 0

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

Add '-4' to each side of the equation.
4 + -4 + -1u = 0 + -4

Combine like terms: 4 + -4 = 0
0 + -1u = 0 + -4
-1u = 0 + -4

Combine like terms: 0 + -4 = -4
-1u = -4

Divide each side by '-1'.
u = 4

Simplifying
u = 4
Solution
u = {-3, 4}