化简：1/x-3+6/9-x^2-x-1/6+2x

1个回答

原式=2(x+3)/[2(x+3)(x-3)]-12/[2(x+3)(x-3)]-(x-1)(x-3)/[2(x+3)(x-3)]
=(2x+6-12-x²+4x-3)/[2(x+3)(x-3)]
=-(x²-6x+9)/[2(x+3)(x-3)]
=-(x-3)²/[2(x+3)(x-3)]
=(3-x)/(2x+6)