1) 1 3/16*8=19/16*8/1=19/2=9 1/2

2)2 1/42*2 6/17=85/45*40/17=100/21=4 16/21

3) 1 11/28*1 3/13=39/28*16/13=12/7=1 5/7

4)9 1/2-4 16/21=19/2-100/21=399/42-200/42=199/42=4 31/42

5)4 31/42-1 5/7=199/42-12/7=199/42-72/42=127/42=3 1/42