解:
原式
=9x4/9+9x1/17+9/17
=4+9/17+9/17
=4+18/17
=5又1/17
9*（4/9+1/17）+9/17=9* 4/9+9* 1/17+9/17=4+9/17+9/17=4+18/17=4+1又1/17=5又1/17
9×（4/9+1/17）+9/17=9+9/17+9/17=9+18/17=10又1/17
