11分之2乘以33又17分之12+20乘以11分之1+11分之1乘以17分之10
=2/11×573/17+20/11+1/11×10/17
=2/11*(573/17+10+5/17)
=2/11*(578/17+10)
=2/11*(34+10)
=2/11*44
=8