7/9*5/6/14/27
=7/9×5/6×27/14
=5/4
=1又1/4
1/2*2/5+9/10/9/20
=1/5+2
=2又1/5
5/8*1/4/5/8*1/4
=1/4×1/4
=1/16
（1/2+2/3+3/4）*36
=1/2×36+2/3×36+3/4×36
=18+24+27
=69