(2/3-4/9+5/27)*27-2又3/17*8+2/17*8
=(2/3)*27 - (4/9)*27 + (5/27)*27 +(-2又3/17+ 2/17)*8
=18- 12 + 5 +(-2 - 1/17)*8
=11-16- 8/17
=-5- 8/17
=-5又8/17
-3又1/7*(-3)+(-1又3/4）*12/7*（5又1/7-1又1/3）
=(3又1/7)*3+(-7/4)*12/7*（4+ 1/7- 1/3）
=(3又1/7)*3 - 3*(4+ 1/7- 1/3)
=3*(3又1/7 - 4 - 1/7 + 1/3)
=3*(-1+ 1/3)
=-3+ 1
=-2