Introductory Algebra for College Students (7th Edition)

$-2x^{20}$
Divide the monomials by cancelling out common factors of the numbers and subtracting the exponents of variables. $\frac{-8x^{22}}{4x^2}=(\frac{-8}{4})x^{(22-2)}=-2x^{20}$ Check the answer. $4x^2\times(-2x^{20})=-8x^{2+20}=-8x^{22}$