( 3 3/4 -2 1/6): 3 1/6+2 2/5*3 1/8= (15/4-13/6):19/6+12/5*25/8= (45/12-26/12)*6/19+ 15/2= 19/12*6/19+15/2= 1/2+15/2= 16/2= 8
(1 1/7+4 2/3):2/7= (8/7+14/3)*7/2= (24/21+98/21)*7/2= 122/21*7/2= 61/3= 20 1/3
(7 1/6 - 2 5/8)*12= (43/6-21/8)*12= (172/24-63/24)*12= 109/24*12= 109/2= 54 1/2