Answer
Then (p _, q) _, r is false and p _, (q _, r) is true
Work Step by Step
To show that these are not logically equivalent.
We need only find one assignment of truth values to p, q, and
r for which the truth values of (p _, q) _, r and p _, (q _, r) differ.
One such assignment is F for all three.
Then (p _, q) _, r is false and p _, (q _, r) is true.
