9=x(4x-9)

Solution for 9=x(4x-9) equation:

Simplifying
9 = x(4x + -9)

Reorder the terms:
9 = x(-9 + 4x)
9 = (-9 * x + 4x * x)
9 = (-9x + 4x2)

Solving
9 = -9x + 4x2

Solving for variable 'x'.

Reorder the terms:
9 + 9x + -4x2 = -9x + 9x + 4x2 + -4x2

Combine like terms: -9x + 9x = 0
9 + 9x + -4x2 = 0 + 4x2 + -4x2
9 + 9x + -4x2 = 4x2 + -4x2

Combine like terms: 4x2 + -4x2 = 0
9 + 9x + -4x2 = 0

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

Subproblem 1
Set the factor '(3 + -1x)' equal to zero and attempt to solve:

Simplifying
3 + -1x = 0

Solving
3 + -1x = 0

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

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

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

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

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

Simplifying
x = 3
Subproblem 2
Set the factor '(3 + 4x)' equal to zero and attempt to solve:

Simplifying
3 + 4x = 0

Solving
3 + 4x = 0

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

Add '-3' to each side of the equation.
3 + -3 + 4x = 0 + -3

Combine like terms: 3 + -3 = 0
0 + 4x = 0 + -3
4x = 0 + -3

Combine like terms: 0 + -3 = -3
4x = -3

Divide each side by '4'.
x = -0.75

Simplifying
x = -0.75
Solution
x = {3, -0.75}