Giải thích các bước giải:

 a, `A=3^19. (1/9)^9`

`=3^18. 3. 1/9^9`

`=9^9. 3 . 1/9^9`

`=3`

b, `B=(1/16)^15: (1/4)^28`

`=1/16^5 : 1/4^28`

`=1/(4^2)^5 . 4^28`

`=1/4^10. 4^28`

`=4^18=2^36`

c, `C=2^5. 5^5- (10^6)/(3. 5^5)`

`=2^5. 5^5-(5^6. 2^6)/(3. 5^5)`

`=2^5. 5^5-(5.2^6)/3`

`=2^5. 5(5^4-2/3)`

`=32. 5 (625-2/3)`

`=160.1250/3`

`=200000/3`

d, `D=(0,25)^4. 2^9+6/(2^5)-16`

`=(1/4)^4. 2^9+3/2^4-16`

`=(1/2)^8 . 2^9 -253/16`

`=1/2^8. 2^9-253/16`

`=2-253/16`

`=-221/16`