Answer
$=-5a^{7}b^{3}$
Work Step by Step
Group factors with the same base: $$\frac{35a^{14}b^{6}}{-7a^{7}b^{3}}$$
$$=(\frac{35}{-7})(\frac{a^{14}}{a^{7}})(\frac{b^{6}}{b^{3}})$$
When dividing factors with the same non-zero base, subtract the exponent of the denominator from the exponent of the numerator:
$$=-5a^{(14-7)}b^{(6-3)}$$
$$=-5a^{7}b^{3}$$