giúp vs ạ ........................

Bài `3:`

`a)`

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

`x^2 = ((-1)/2)^2 . ((-2)/3)^2`

`x^2=((-1)/2 .((-2)/3)^2`

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

`x^2=1/9`

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

Suy ra `x in {1/3;(-1)/3}`

Vậy `x in {1/3; (-1)/3}`

`b)`

`x^2 . x^3=32`

`x^5 = 2^5`

Suy ra `x=2`

Vậy `x=2`

`c)`

`(-0,27)^8 : x^3 = (-0,27)^5`

`x^3=(-0,27)^8 : (-0,27)^5`

`x^3=(-0,27)^3`

Suy ra `x=-0,27`

Vậy `x=-0,27`

`d)`

`27^5 . x^15 = 9^15`

`3^15 . x^15 = 9^15`

`x^15 = 9^15 : 3^15`

`x^15 = (9:3)^15`

`x^15=3^15`

Suy ra `x=3`

Vậy `x=3`

`e)`

`x^2+1=10`

`x^2=10-1`

`x^2=9`

`x^2=(+-3)^2`

Suy ra `x in {3;-3}`

Vậy `x in {3;-3}`

`f)`

`(x+2)^3=64`

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

Suy ra`:`

`x+2=4`

`x=4-2`

`x=2`

Vậy `x=2`

Bài `4:`

`a)`

`(1/2)^2 . x= (1/2)^5`

`x=(1/2)^5 : (1/2)^2`

`x=(1/2)^3`

`x=1/8`

Vậy `x=1/8`

`b)`

`x:(-3/5)^2= (-3/5)`

`x=(-3/5) . (-3/5)^2`

`x=(-3/5)^3`

`x=(-27)/125`

Vậy `x=(-27)/125`

`c)`

`(1/3)^3  . x= 1/81`

`x=(1/3)^4 : (1/3)^3`

`x=1/3`

Vậy `x=1/3`