4целых 5/12 × 6/53 , 2 целых 5/11× 1 целая 19/36, 8 × 2/5 × 1 целая 9/16

1) 4 5/12 * 6/53 = 53/12 * 6/53 = 53*6/12*53 = 1/2

2) 2 5/11 * 1 19/36 = 27/5 * 55/36 = 27*55/5*36 = 33/4 = 8 1/4

3) 8 * 2/5 * 1 9/16 = 8/1 * 2/5 * 25/16 = 8*2*25 / 1*5*16 = 10/2 = 5