We know that the numerical coefficients of given numerical are 12, 6 and 2

Greatest common factor of 12, 6 and 2 is 2.

Common literals appearing in given numerical are a and x

Smallest power of x in three monomials is 2

Smallest power of a in three monomials is 1

Monomials of common literals with smallest power is ax^{2}

∴ The greatest common factor = 2ax^{2}

Divide as directed (x^{4} – 81) ÷ (x^{3} + 3x^{2} + 9x + 27)

Divide as directed (3x^{3} – 6x^{2} – 24x) ÷ (x – 4) (x + 2)

Divide as directed 15(y + 3)(y^{2} – 16) ÷ 5(y^{2} – y – 12)