Answer
a. yes
b. no
Work Step by Step
$A = \{x|x ∈ N$ and $6 \leq x \lt 10\}$
$B = \{x|x ∈ N$ and $9 \lt x \leq 13\}$
Expressed using the roster method:
$A = \{6, 7, 8, 9\}$
$B = \{10, 11, 12, 13\}$
a. Those sets are equivalent as they have the same number of elements.
b. Those sets aren't equal, as their elements are not all the same.