5u^2+9u=-4

Solution for 5u^2+9u=-4 equation:

Simplifying
5u2 + 9u = -4

Reorder the terms:
9u + 5u2 = -4

Solving
9u + 5u2 = -4

Solving for variable 'u'.

Reorder the terms:
4 + 9u + 5u2 = -4 + 4

Combine like terms: -4 + 4 = 0
4 + 9u + 5u2 = 0

Factor a trinomial.
(1 + u)(4 + 5u) = 0

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

Simplifying
1 + u = 0

Solving
1 + u = 0

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

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

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

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

Simplifying
u = -1
Subproblem 2
Set the factor '(4 + 5u)' equal to zero and attempt to solve:

Simplifying
4 + 5u = 0

Solving
4 + 5u = 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 + 5u = 0 + -4

Combine like terms: 4 + -4 = 0
0 + 5u = 0 + -4
5u = 0 + -4

Combine like terms: 0 + -4 = -4
5u = -4

Divide each side by '5'.
u = -0.8

Simplifying
u = -0.8
Solution
u = {-1, -0.8}