(7 1/2+3 2/3)*6; (9-1 1/7)*7

(7 1/2 + 3 2/3) * 6 = 67

1) 7 1/2 + 3 2/3 = 7 3/6 + 3 4/6 = 10 7/6 = 11 1/6

2) 11 1/6 * 6 = 67/6 * 6 = 67

(9 - 1 1/7) * 7 = 55

1) 9 - 1 1/7 = 8 7/7 - 1 1/7 = 7 6/7

2) 7 6/7 * 7 = 55/7 * 7 = 55