[tex]2 - \frac{x+1}{x-2} - \frac{x-4}{x+2} = \frac{2(x-2)(x+2)}{(x-2)(x+2)} - \frac{(x+1)(x+2)}{(x-2)(x+2)} - \frac{(x-4)(x-2)}{(x-2)(x+2)} \\= \frac{2(x-2)(x+2)-(x+1)(x+2)-(x-4)(x-2)}{(x-2)(x+2)} \\= \frac{2x^{2} -8-x^{2}-3x-2-x^{2} +6x-8 }{x^{2} -4} \\=\frac{3x+(-18)}{x^{2} -4}[/tex]
so : a = 3 b = -18
ok done. Thank to me :>
