5.5*0.8+3.6/1.2-6.5*0.6
=4.4+3-3.9
=3+0.5
=3.5
2/3+2/15+2/35+2/63+2/99+1/11
=12/15+2/35+2/63+11/99
=4/5+2/35+2/63+1/9
=30/35+9/63
=6/7+1/7
=1