(x2×y3×z4)2=
Let's solve this in two stages. In the first stage, we'll use the power law for power of a product in parentheses:
which states that when raising a product in parentheses to a power, the power applies to each factor of the product when opening the parentheses,
Let's apply this law to our problem:
where when opening the parentheses, we applied the power to each factor of the product separately, but since each of these factors is raised to a power, we did this carefully and used parentheses,
Next, we'll use the power law for power of a power:
Let's apply this law to the expression we got:
where in the second stage we performed the multiplication operation in the power exponents of the factors we obtained.
Therefore, the correct answer is answer D.
Note:
From the above formulation of the power law for parentheses, it might seem that it only refers to two factors in a product within parentheses, but in fact, it is valid for a power of a product of multiple factors in parentheses, as demonstrated in this problem and others,
It would be a good exercise to prove that if the above law is valid for a power of a product of two factors in parentheses (as it is formulated above), then it is also valid for a power of a product of multiple factors in parentheses (for example - three factors, etc.).