Đáp án`+`Giải thích các bước giải:

`a)`

 `M = (x^2/(x^3 -4x) + 6/(6-3x) + 1/(x+2)) : (x-2+(10-x^2)/(x + 2)) (ĐKXĐ: x ne +-2) `

`M =  (x^2/(x(x^2-4)) - 6/(3x-6) + 1/(x+2)) : (x-2+(10-x^2)/(x + 2))`

`M =  ((3x^2)/(3x(x-2)(x+2)) - (6x(x+2))/(3x(x-2)(x+2)) + (3x(x-2))/(3x(x-2)(x+2))) : (((x-2)(x+2))/(x+2)+(10-x^2)/(x + 2))`

`M = (3x^2 - 6x^2 - 12x + 3x^2 - 6x)/(3x(x-2)(x+2)) : (x^2 - 4 + 10 -x^2)/(x+2)`

`M = (-18x)/(3x(x-2)(x+2)) : 6/(x+2)`

`M = (-6)/((x-2)(x+2)) *(x+2)/6`

`M = 1/(2-x)`

`b)`

Khi `x=-1 `

`M = 1/(2-(-1)) = 1/3`

`c)`

`M = 1/(2-x) = -2`

`-2(2-x) = 1`

`2x-4 = 1`

`2x = 5`

`x= 5/2`

Vậy `x=5/2`

`d)`

`M in Z ` khi `1/(2-x) in Z`

Khi ` 2-x in Ư(1) ={+-1}`

`x in {1;3} (x in Z)`