`Q = ((sqrt x + 2)/(x + 2 sqrt x + 1) - (sqrt x - 2)/(x -1)) . (sqrt x + 1)/(sqrt x) (x ge 0 ; x ne 1)`

`Q = (((sqrt x + 2)(sqrt x - 1))/((x-1)(sqrt x + 1)) - ((sqrt x - 2)(sqrt x + 1))/((sqrt x + 1)(x-1))) . (sqrt x + 1)/(sqrt x)` 

`Q = (x + sqrt  x - 2 - x + sqrt x + 2)/((sqrt x +1)(x-1)) . (sqrt x + 1)/(sqrt x)`

`Q = (2 sqrt x)/(sqrt x (x-1))`

`Q = 2/(x-1)`

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`x^2-5x+4=0`

`(x-1)(x-4)=0`

`-> x-1=0;x-4=0`

`->x=1;x=4`