(1)[5/8]+[3/5]+[3/8],
=[5/8]+[3/8]+[3/5],
=1+[3/5],
=1[3/5];
(2)[17/18]+[4/15]+[1/18]+[11/15],
=([17/18]+[1/18])+([11/15]+[4/15]),
=1+1,
=2.
(1)[5/8]+[3/5]+[3/8],
=[5/8]+[3/8]+[3/5],
=1+[3/5],
=1[3/5];
(2)[17/18]+[4/15]+[1/18]+[11/15],
=([17/18]+[1/18])+([11/15]+[4/15]),
=1+1,
=2.