1 1/3×3 1/4=?; 3/4×1 1/3=?; 2/11×1 5/6=?; 5 5/7×9/20=?; 3 5/9×4 7/8=?; 2 1/12×8/11=?; найдите чему равны произведения

1) 1 1/3 * 3 1/4 = 4/3 * 13/4 = 4*13/3 *4 = 13/3 = 4 1/3 2) 3/4 * 1 1/3 = 3/4 * 4/3 = 3*4/4*3 = 1/1 = 1  3) 2/11 * 1 5/6 = 2/11 * 11/6 = 2*11/11*6 = 2/6 = 1/3 4) 5 5/7 * 9/20 = 40/7 * 9/20 = 40*9/7*20 = 2*9/7*1 = 18/7 = 2 4/7 5) 3 5/9 * 4 7/8 = 32/9 * 39/8 = 32*39/9*8 = 4*39/9*1 = 156/9 =17 3/9 = 17 1/3 6) 2 1/12 * 8/11 = 25/12 * 8/11 = 25*8/12*11 = 25*2/3*11 = 50/33 = 1 17/33