f(x)=(x^2+1)(x^3-x)

Solution for f(x)=(x^2+1)(x^3-x) equation:

Simplifying
f(x) = (x2 + 1)(x3 + -1x)

Multiply f * x
fx = (x2 + 1)(x3 + -1x)

Reorder the terms:
fx = (1 + x2)(x3 + -1x)

Reorder the terms:
fx = (1 + x2)(-1x + x3)

Multiply (1 + x2) * (-1x + x3)
fx = (1(-1x + x3) + x2(-1x + x3))
fx = ((-1x * 1 + x3 * 1) + x2(-1x + x3))
fx = ((-1x + 1x3) + x2(-1x + x3))
fx = (-1x + 1x3 + (-1x * x2 + x3 * x2))
fx = (-1x + 1x3 + (-1x3 + x5))

Combine like terms: 1x3 + -1x3 = 0
fx = (-1x + 0 + x5)
fx = (-1x + x5)

Solving
fx = -1x + x5

Solving for variable 'f'.

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

Divide each side by 'x'.
f = -1 + x4

Simplifying
f = -1 + x4