We consider a simple Newtonian model of a non-rotating white dwarf containing a dark-matter admixture. The baryonic component is described by the Chandrasekhar equation of state for a cold degenerate electron gas, whereas the dark component is modeled as an independent polytropic fluid. The two components are coupled only through the common Newtonian gravitational field. Numerical solutions are constructed for a reference baryonic sequence and for representative mixed configurations with fixed dark-sector parameters. Attention is restricted to three basic outputs: the density profiles, the mass–radius relation, and the limiting mass readout within the explored density interval. The goal is not to identify a specific dark-matter particle model, but to provide a transparent baseline calculation showing how an additional gravitating component can modify the equilibrium sequence of white dwarfs.