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`
