Final answer:
The equivalent weight of a metal in a metal oxide with total weight x grams and oxygen weight y grams is calculated as x - y. This represents the metal's weight without the oxygen's weight in the compound.
Step-by-step explanation:
If the weight of metal oxide is x grams which contains y grams of oxygen, the equivalent weight of the metal can be found by subtracting the weight of the oxygen from the total weight of the metal oxide. This is because the metal oxide consists of metal and oxygen, and by knowing the total mass and the mass of oxygen, we can deduce the mass of the metal alone. Therefore, the equivalent weight of the metal is given by x - y. This calculation is significant in stoichiometry, where understanding the masses in chemical reactions is crucial.