Tính B=(5.4^15.9^9-4.3^20.9^9)/(5.2^9.6^19-7.2^29.27^6)

Mình làm theo 2 trường hợp vì đề có vẻ sai nhé !

1) (có vẻ sai đề)

`B = (5 . 4^15 . 9^9 – 4 . 3^20 . 9^9)/(5 . 2^9 . 6^19 – 7 . 2^29 . 27^6)`

`= (5 . (2^2)^15 . (3^2)^9 – 2^2 . 3^20 . (3^2)^9)/(5 . 2^9 . (2 . 3)^19 – 7 . 2^29 . (3^3)^6)`

`= (5 . 2^30 . 3^18 – 2^2 . 3^20 . 3^18)/(5 . 2^9 . 2^19 . 3^19 – 7 . 2^29 . 3^18)`

`= (5 . 2^2 . 2^28 . 3^18 – 2^2 . 3^20 . 3^18)/(5 . 2^28 . 3^18 . 3 – 7 . 2^28 . 2 . 3^18)`

`= (2^2 . 3^18 . (5 . 2^28 – 3^20))/(2^28 . 3^18 . (5 . 3 – 7 . 2))`

`= (5 . 2^28 – 3^20)/(2^26)`

`= 20 – (3^10)/(2^26)`

2) (đúng đề)

`B = (5 . 4^15 . 9^9 – 4 . 3^20 . 8^9)/(5 . 2^9 . 6^19 – 7 . 2^29 . 27^6)`

`= (5 . (2^2)^15 . (3^2)^9 – 2^2 . 3^20 . (2^3)^9)/(5 . 2^9 . (2 . 3)^19 – 7 . 2^29 . (3^3)^6)`

`= (5 . 2^30 . 3^18 – 2^2 . 3^20 . 2^27)/(5 . 2^9 . 2^19 . 3^19 – 7 . 2^29 . 3^18)`

`= (5 . 2^30 . 3^18 – 2^29 . 3^20)/(5 . 2^28 . 3^19 – 7 . 2^29 . 3^18)`

`= (2^29 . 3^18 . (5 . 2 – 3^2))/(2^28 . 3^18 . (5 . 3 – 7 . 2))`

`= (2 . 1 . 1)/(1 . 1 . 1)`

`= 2`