`#tnvt`
`7)\frac{x+2}{x-1}+\frac{3}{x+1}-\frac{x^2}{x^2-1}(x\ne+-1)`
`=\frac{(x+1)(x+2)+3(x-1)-x^2}{x^2-1}`
`=\frac{x^2+3x+2+3x-3-x^2}{x^2-1}`
`=\frac{6x-1}{x^2-1}`
`8)\frac{x+1}{x-3}-\frac{2}{x+3}-\frac{4x}{9-x^2}(x\ne+-3)`
`=\frac{(x+1)(x+3)-2(x-3)+4x}{(x+3)(x-3)}`
`=\frac{x^2+4x+3-2x+6+4x}{(x-3)(x+3)}`
`=\frac{x^2+6x+9}{(x-3)(x+3)}`
`=\frac{(x+3)^2}{(x-3)(x+3)}`
`=\frac{x+3}{x-3}`