Đáp án + Giải thích các bước giải:

Bài 1:

`a) x : (-1/2)^3 = -1/2`

    `x : (-1/8) = -1/2`

    `x = -1/2 . (-1/8)`

    `x = 1/16`

Vậy `x = 1/16`

`b) x . (3/5)^7 = (3/5)^9`

    `x = (3/5)^9 : (3/5)^7`

    `x = (3/5)^2`

    `x = 9/25`

Vậy `x = 9/25`

`c) (-2/3)^11 : x = (-2/3)^9`

    `x = (-2/3)^11 : (-2/3)^9`

    `x = (-2/3)^2`

    `x = 4/9`

Vậy `x = 4/9`

`d) x . (0,25)^6 = (1/4)^8`

    `x . (1/4)^6 = (1/4)^8`

    `x = (1/4)^8 : (1/4)^6`

    `x = (1/4)^2`

    `x = 1/16`

Vậy `x = 1/16`

Bài 6:

`a) [(3/7)^4 . (3/7)^5] : (3/7)^7`

`= (3/7)^9 : (3/7)^7`

`= (3/7)^2`

`= 9/49`

`b) [(7/8)^5 : (7/8)^4] . 7/8`

`= 7/8 . 7/8`

`= 49/64`

`c) [(0,6)^3 . (0,6)^8] : [(0,6)^7 . (0,6)^2]`

`= (0,6)^11 : (0,6)^9`

`= (0,6)^2`

`= 0,36`

Bài 7:

`a) (2/5 + 1/2)^2`

`= (9/10)^2`

`= 81/100`

`b) (0,75 - 1 1/2)^3`

`= (0,75 - 3/2)^3`

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

`= (-3/4)^3`

`= -27/64`

`c) (3/5)^11 : (0,36)^5`

`= (3/5)^11 : (9/25)^5`

`= (3/5)^11 : [(3/5)^2]^5`

`= (3/5)^11 : (3/5)^10`

`= 3/5`

`d) (1 - 1/3)^8 : (4/9)^3`

`= (2/3)^8 : [(2/3)^2]^3`

`= (2/3)^8 : (2/3)^6`

`= (2/3)^2`

`= 4/6`