Answer 1

A = {6, 7, 8, 9}

B = {4, 6, 8, 10}

C = {x : x ∈ N : 2 < x ≤ 7}

= {3, 4, 5, 6, 7}

A - C = {6, 7, 8, 9} - {3, 4, 5, 6, 7}

= {8, 9}

B - (A - C) = {4, 6, 8, 10} - {8, 9}

= {4, 6, 10}