Answer:
30.95 cm
Step-by-step explanation:
The focal length f, the object distance do, and the image distance di are related with the following equation:

So, replacing the values, we get:

Then, solving for di, we get:
![\begin{gathered} (1)/(6.25)-(1)/(5.2)=(1)/(d_i) \\ -(21)/(650)=(1)/(d_i)_{} \\ -(650)/(21)=d_i \\ -30.95\operatorname{cm}=d_i \end{gathered}]()
Therefore, the image distance is 30.95 cm