`b)`
`(x^2)/(x+1) + (2x)/(x^2-1) - 1/(1-x) + 1 (x \ne +-1)`
`= (x^2)/(x+1) + (2x)/(x^2-1) + 1/(x-1) + 1`
`= (x^2 (x-1) + 2x + 1 (x+1) + (x^2 - 1))/(x^2- 1)`
` = (x^3 - x^2+ 2x + x + 1 + x^2-1)/(x^2-1)`
`= (x^3 + 3x)/(x^2 - 1)`
`c)`
`1/(x^3-x) - 1/((x-1)x) + 2/(x^2-1) ( x \ne +-1 ; x \ne 0)`
`= (1 - (x+1) + 2x)/(x^3 -x)`
` = (1 -x - 1 + 2x)/(x^3-x)`
` = x/(x(x^2-1))`
` = 1/(x^2-1)`
