（2/3+3）(3-2/3x)+(-2/3-1)(1+2/3x)
=(2+9-4/9x-2x)+(-2/3-1-4/9x-2/3x)
=2+9-4/9x-2x-2/3-1-4/9x-2/3x
=2+9-2/3-1-4/9x-2x-4/9x-2/3x
=28/3-32/9x
好好学习*@*