Đáp án + Giải thích các bước giải:

 `s, 21^3/7^4`

`= (7.3)^3/7^4`

$=\frac{7^3.3^3}{7^4}$ 

$=\frac{1.3^3}{7}$ 

$=\frac{27}{7}$ 

`t,` $55^3/11^5$

` = (5.11)^3/11^5`

$ = \frac{5^3.11^3}{11^5}$ 
$= \frac{5^3.1}{11^2}$ 

$= \frac{125}{121}$ 

`u, 6^6/3^8`

` = (3.2)^6/3^8`

$ = \frac{3^6.2^6}{3^8}$ 

$= \frac{1.2^6}{3^2}$ 

$= \frac{64}{9}$ 

`v ,45^2/-9^4`

` = (5.9)^2/-9^4`

$= \frac{5^2.9^2}{-9^4}$ 

$= \frac{5^2.1}{-9^2}$ 

$= \frac{25}{-81}$ $=-25/81$

$y, 8^10/4^8$

` = (2.4)^10/4^8`

$=2^{10}.4^{10}$ `/` $4^{8}$ 

 $=2^{10}.4^{2}/1$ 

$= 16384$