Expert, please help me. How to solve the question of this type:

3. In the following APs, find the missing terms in the boxes:

$$\begin{gathered} \left(\mathrm{i}\right) 2, \boxed{ \\ }, 26 \\ \left(\mathrm{ii}\right) \boxed{ \\ }, 13, \boxed{ \\ }, 3 \\ \left(\mathrm{iii}\right) 5, \boxed{ \\ }, \boxed{ \\ }, 9\frac{1}{2} \\ \left(\mathrm{iv}\right) -4, \boxed{ \\ }, \boxed{ \\ }, \boxed{ \\ }, \boxed{ \\ }, 6 \\ \left(\mathrm{v}\right) \boxed{ \\ }, 38, \boxed{ \\ }, \boxed{ \\ }, \boxed{ \\ }, -22 \end{gathered}$$