Question

 giúp mik vs

Answer 1

`[x+2]/[x-1]([x^3]/[x+1]+2)-[8x+7]/[x^2-1]`      (với `x ne +-1`)

`=[x+2]/[x-1].[x^3+2x+2]/[x+1]-[8x+7]/[(x-1)(x+1)]`

`=[(x+2)(x^3+2x+2)-8x-7]/[(x-1)(x+1)]`

`=[x^4+2x^2+2x+2x^3+4x+4-8x-7]/[(x-1)(x+1)]`

`=[x^4+x^3+x^3+x^2+x^2+x-3x-3]/[(x-1)(x+1)]`

`=[(x+1)(x^3+x^2+x-3)]/[(x-1)(x+1)]`

`=[x^3-x^2+2x^2-2x+3x-3]/[x-1]`

`=[(x-1)(x^2+2x+3)]/[x-1]=x^2+2x+3`