(1 9/16*3 1/5+1 2/3-9: 2 2/5): (17 7/12-6 1/3)

(1 9/16*3 1/5+1 2/3-9:2 2/5):(17 7/12-6 1/3)=

=[(25/16)·16/5 +5/3-9 ·5/12]:(17 7/12-6 4/12)=[5+5/3-15/4]:(11  3/12)=

=[5+1 2/3-3 3/4]:(11  3/12)=[5+1 8/12-3 9/12]:(11  3/12)=

=(6   8/12 -3 9/12)·(12/143)= (2  11/12)·(12/143)=(35/12)(12/143)=35/143