Giúp tớ câu b vs ạaa

Đáp án+Giải thích các bước giải:

`b) (4^5 . 9^4 - 2 . 6^9)/(2^10 . 3^8 + 6^8 . 20)`

`= ( (2^2)^5 . (3^2)^4 - 2 . (2 . 3)^9)/(2^10 . 3^8 + (2 . 3)^8 . 2^2 . 5)`

`= (2^10 . 3^8 - 2 . 2^9 . 3^9)/(2^10 . 3^8 + 2^8 . 3^8 . 2^2 . 5)`

`= (2^10 . 3^8 - 2^10 . 3^8 . 3)/(2^10 . 3^8 + 2^10 . 3^8 . 5)`

`= ((2^10 . 3^8)(1 - 3))/((2^10 . 3^8)(1 + 5))`

`= (-2)/6`

`= (-1)/3`

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`b) (1/4 x - 1/8) . 3/4 = 1/4`

`1/4x - 1/8 = 1/4 : 3/4`

`1/4x - 1/8 = 1/3`

`1/4x = 1/3 + 1/8`

`1/4x = 11/24`

`x = 11/24 : 1/4`

`x = 11/6`

Vậy ..............