Missing question: Z:X = 7:1 A:Z = 2.5:1 A:Z = 2.2:1 Y:X = 11:1.
Answer is: Z:X = 7:1 and Y:X = 11:1.
Law of multiple proportions or Dalton's Law said that the ratios of the masses of the second element which combine with a fixed mass of the first element will be ratios of small whole numbers.
In this example ratios are whole numbers, A:Z = 2.5 : 1 and A:Z = 2.2 : 1 are not whole number ratios.