`ĐKXĐ: x\ne0; x\ne1; x\ne-2`
`P=(x-3+1/(x-1)):(x-1+1/(1-x)):(x+2)/x`
`P=(x(x-1)-3(x-1)+1)/(x-1):(x(1-x)-(1-x)+1)/(1-x).(x)/(x+2)`
`P=(x^2-x-3x+3+1)/(x-1):(x-x^2-1+x+1)/(1-x).(x)/(x+2)`
`P=(x^2-4x+4)/(x-1):(2x-x^2)/(1-x).(x)/(x+2)`
`P=(x-2)^2/(x-1):(x(2-x))/(1-x).(x)/(x+2)`
`P=(x-2)^2/(x-1).(1-x)/(x(2-x)).(x)/(x+2)`
`P=(x-2)^2/(x-1).(x-1)/(x(x-2)).(x)/(x+2)`
`P=(x-2)/(x+2)`
Vậy với `x\ne0; x\ne1; x\ne-2` thì `P=(x-2)/(x+2)`
