--> a/b : c/d = a.d/b.c --> a,b = ab/10 --> a b/c = (a.c + b)/c =[6/5 * 5/6 + 35/10](3/20 - 1) 16/3 =[ 1 + 7/2](-17/20) 16/3 =[ 9/2 ] (-17/20) 16/3=-51/20