四分之一×（4.85÷十八分之五—3.6+6.15×3又五分之三）+[5.5—1.75×（1又三分之二+二十一分之十九）]
=四分之一×（4.85×3.6—3.6+6.15×3.6）+[5.5—1.75×（5/3+19/21）]
=1/4×3.6×（4.85-1+6.15）+5.5-1.75×5/3-1.75×18/7
=0.9×10+5.5- 4.5
=9+1
=10