选择题
2000 AMC 8 Problem 17: Custom Operation
The operation ⊗ is defined for all nonzero numbers by a ⊗ b = a²/b. Determine [(1 ⊗ 2) ⊗ 3] − [1 ⊗ (2 ⊗ 3)].
A.
−2/3
B.
−1/4
C.
0
D.
1/4
E.
2/3