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Đáp án:

Giải thích các bước giải:

 Ta có:

`a) 3x^2 - 4x = 0`

`=> x(3x - 4) =0`

`=> [(x=0),(3x - 4=0):}`

`=> [(x=0),(3x =4):}`

`=> [(x=0),(x=4/3):}`

Vậy `x in {0; 4/3}`

`c) x(3x  -1) - 3x + 1 = 0`

`=> x(3x - 1) - (3x - 1) = 0`

`=> (3x - 1) (x - 1)= 0`

`=>[ (3x - 1=0) ,(x - 1= 0):}`

`=>[ (3x =1) ,(x = 0+1):}`

`=>[ (x =1/3) ,(x = 1):}`

Vậy `x in { 1/3;1}`

`e) x^3 + x^2 - 4x - 4 = 0`

`=> x^2(x + 1) - 4(x + 1) = 0`

`=> (x + 1) (x^2 - 4)= 0`

`=> (x + 1)(x - 2)(x + 2) = 0`

`=> [(x + 1=0),(x - 2=0),(x + 2= 0):}`

`=> [(x =-1),(x =2),(x = -2):}`

Vậy `x in {-1;2;-2}`