f(x)=(x-9)(x+6)

Solution for f(x)=(x-9)(x+6) equation:

Simplifying
f(x) = (x + -9)(x + 6)

Multiply f * x
fx = (x + -9)(x + 6)

Reorder the terms:
fx = (-9 + x)(x + 6)

Reorder the terms:
fx = (-9 + x)(6 + x)

Multiply (-9 + x) * (6 + x)
fx = (-9(6 + x) + x(6 + x))
fx = ((6 * -9 + x * -9) + x(6 + x))
fx = ((-54 + -9x) + x(6 + x))
fx = (-54 + -9x + (6 * x + x * x))
fx = (-54 + -9x + (6x + x2))

Combine like terms: -9x + 6x = -3x
fx = (-54 + -3x + x2)

Solving
fx = -54 + -3x + x2

Solving for variable 'f'.

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

Divide each side by 'x'.
f = -54x-1 + -3 + x

Simplifying
f = -54x-1 + -3 + x

Reorder the terms:
f = -3 + -54x-1 + x