1. $(x^{-2--2}y^{-6-4})^2$
$(1\cancel{x^0}y^{-10})^2$
$y^{-20}\text{ or }\dfrac{1}{y^{20}}$
2. $(x^{-3--1}y^{-3-6})^3$
$(x^{-2}y^{-9})^3$
$x^{-6}y^{-27}\text{ or }\dfrac{1}{x^6y^{27}}$
3. $(x^{-2-2}y^{-4--4})^2$
$(x^{-4}\cancel{y^0}1)^2$
$x^{-8}\text{ or }\dfrac{1}{x^8}$
4. $(x^{-5--4}y^{-3-2})^4$
$(x^{-1}y^{-5})^4$
$x^{-4}y^{-20}\text{ or }\dfrac{1}{x^4y^{20}}$
5. $(x^{-2--3}y^{-2-3})^8$
$(x^1y^{-5})^8$
$x^8y^{-40}\text{ or }\dfrac{x^8}{y^{40}}$
6. $(x^{-4--3}y^{-3-2})^5$
$(x^{-1}y^{-5})^5$
$x^{-5}y^{-25}\text{ or }\dfrac{1}{x^5y^{25}}$
7. $(x^{-2--2}y^{-4-4})^{-2}$
$(1\cancel{x^0}y^{-8})^{-2}$
$y^{16}$
8. $(x^{-2--5}y^{-3-3})^{-3}$
$(x^3y^{-6})^{-3}$
$x^{-9}y^{18}\text{ or }\dfrac{y^{18}}{x^9}$
9. $(x^{-2--2}y^{-3--3})^{-1}$
$(\cancel{x^0y^0}1)^{-1}$
1
10. ${(x^{-2--2}y^{-3--4})}^{-2}$
$(x^0y^{-7})^{-2}$
$y^{14}$
11. $\left(\dfrac{1\cancel{x^0}y^{-3}}{x^{-2}\cancel{y^0}1}\right)^{-5}$
$\phantom{a}$
$\left(\dfrac{x^2}{y^3}\right)^{-5}$
$\phantom{a}$
$\dfrac{x^{-10}}{y^{-15}}$
$\phantom{a}$
$\dfrac{y^{15}}{x^{10}}$
12. 1
13. $\left(\dfrac{1 \cancel{a^0}b^3}{a^6b^{-12}}\right)^{-\frac{1}{3}}$
$\phantom{a}$
$\left(\dfrac{b^{15}}{a^6}\right)^{-\frac{1}{3}}$
$\phantom{a}$
$\dfrac{b^{-5}}{a^{-2}}\text{ or }\dfrac{a^2}{b^5}$
14. $(a^4b^4c^{12})^{\frac{1}{4}}$
$abc^3$
15. $\left(\dfrac{a^5c^{10}d^{15}}{b^5}\right)^{\frac{2}{5}}$
$\phantom{a}$
$\dfrac{a^2c^4d^6}{b^2}$
16. $\left(\dfrac{b^{20}}{a^4}\right)^{-\frac{3}{4}}$
$\phantom{a}$
$\dfrac{b^{-15}}{a^{-3}}\text{ or }\dfrac{a^3}{b^{15}}$
17. 1
18. Undefined