9÷3/7; 2÷1 1/3; 2 1/7÷15;
9:37 = 9*7/3 = 3*7 = 21 2:1 1/3 = 2:4/3 = 2*3/4 = 3/2 2 1/7:15 = 15/7:15 = 15/7*1/15 = 1/7