If a polynomial function has integer coefficients, then every rational zero will have the form where is a factor of the constant and is a factor of the leading coefficient.

Find every combination of . These are the possible roots of the polynomial function.

Substitute into the polynomial.

Simplify each term.

Raise to the power of .

Raise to the power of .

Multiply by .

Multiply by .

Subtract from .

Add and .

Subtract from .

Since is a known root, divide the polynomial by to find the quotient polynomial. This polynomial can then be used to find the remaining roots.

Divide by .

Write as a set of factors.

Write as a Set of Linear Factors x^3-9x^2+25x-21