Final answer:
The preimage of C'(-3,-10) under the given translation is (-11,-6).
Step-by-step explanation:
To find the preimage of C'(-3,-10), we need to apply the translation (x,y) -> (x-8,y+4) to C'(-3,-10).
Substituting the values, we have (-3-8,-10+4) which simplifies to (-11,-6). Therefore, the preimage of C'(-3,-10) is (-11,-6).