(3 1/2-2 2/3+5 5/6+4 3/5)*1 2/13=

(3 1/2 - 2 2/3 + 5 5/6 + 4 3/5) * 1 2/13 = 131) 3 1/2 - 2 2/3 = 3 3/6 - 2 4/6 = 2 9/6 - 2 4/6 = 5/62) 5/6 + 5 5/6 = 5 10/6 = 6 4/6 = 6 2/33) 6 2/3 + 4 3/5 = 6 10/15 + 4 9/15 = 10 19/15 = 11 4/154) 11 4/15 * 1 2/13 = 169/15 * 15/13 = 169/13 = 13