(2-1 7/12)\(3/8-1/6)=
( 2 - 1 7/12) / ( 3/8 - 1/6) = = 4/12 / ( 9/24 - 4/24) = =4/12 : 5/24 = 4/12 * 24/5 = = 8/5= 1 3/5