9u^2+5u-4=0

Solution for 9u^2+5u-4=0 equation:

Simplifying
9u2 + 5u + -4 = 0

Reorder the terms:
-4 + 5u + 9u2 = 0

Solving
-4 + 5u + 9u2 = 0

Solving for variable 'u'.

Factor a trinomial.
(-1 + -1u)(4 + -9u) = 0

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

Simplifying
-1 + -1u = 0

Solving
-1 + -1u = 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 + -1u = 0 + 1

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

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

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

Simplifying
u = -1
Subproblem 2
Set the factor '(4 + -9u)' equal to zero and attempt to solve:

Simplifying
4 + -9u = 0

Solving
4 + -9u = 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 + -9u = 0 + -4

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

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

Divide each side by '-9'.
u = 0.4444444444

Simplifying
u = 0.4444444444
Solution
u = {-1, 0.4444444444}