Answer
$=4x^{16}$
Work Step by Step
Group factors with the same base: $$\frac{8x^{20}}{2x^{4}}$$
$$=(\frac{8}{2})(\frac{x^{20}}{x^{4}})$$
When dividing factors with the same non-zero base, subtract the exponent of the denominator from the exponent of the numerator:
$$=4x^{(20-4)}$$
$$=4x^{16}$$
