Giúp mik với ạ cảm ơn 

`a) (3/5)^5 . x = (3/7)^7`

`x= (3/7)^7 : (3/5)^5`

`x= (3/7)^7 . (5/3)^5`

`x= 28125/49`

`b) (-1/3)^8 . x = 1/81`

`x = 1/(3^3) : (1/3)^8`

`x = 1/(3^3) . 3^8`

`x = 3^5 = 243`

`c) (x-1/2)^8 = 1/27`

`x-1/2 = +- \root{8}{27}`

`x = +- \root{8}{27} + 1/2`

`d) (x+1/2)^4 = 16/81`

`(x+1/2)^4 = (2/3)^4`

`x+1/2=2/3`

`x=2/3-1/2=1/6`

`e) x^8 = -27`

Vì `x^8 >= 0  (AA x in RR)`

mà `-27 < 0`

`=> x` không có nghiệm `x` thỏa mãn

`f) (2x-1)^8 = 8`

`2x-1 = +- \root{8}{8}`

`x = (+- \root{8}{8} + 1)/2`