Answer:
 x·y·x·y
Step-by-step explanation:
You want the expanded form of (xy)².
Multiplication
The exponent tells the number of times the expression is a factor in the product:
 (xy)² = (xy)·(xy)
Placing variables next to each other signifies multiplication, so this expression expands to ...
 x·y·x·y
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Additional comment
The commutative property of multiplication says you can arrange these factors in any convenient order. Often, we like to arrange them in alphabetical order:
 = x·x·y·y
