Problem: Of the following expressions the one equal to a−3−b−3a−1b−1​ is:
Answer Choices:
A. b2−a2a2b2​
B. b3−a3a2b2​
C. b3−a3ab​
D. aba3−b3​
E. a−ba3b3​
Solution:
a−3−b−3a−1b−1​⋅a3b3a3b3​=b3−a3a2b2​