(27+18/19)/9
=27÷9+18/19÷9
=3+2/19
=3又2/19
(51/10+17/38)*51分之19
=51/10x19/51+17/38x19/51
=19/10+1/6
=57/30+5/30
=62/30
=31/15
(2又5分之4+1又7分之4)-(2又5分之4-1又7分之4)
=(2又4/5-2又4/5)+(1又4/7-1又4/7)
=0+0
=0
17/(17+17/20)
=17÷[17x(1+1/20)]
=17÷17÷21/20
=20/21
108*(1/3+1/6+1/9)
=108x1/3+108x1/6+108x1/9
=36+18+12
=66