Step 1: Use Vieta's relations.
Vieta’s relations give the sum and product of the roots of a quadratic equation. By substituting \( c \) and \( d \) in the second equation, we can find one of the roots.
Step 2: Conclusion.
After applying Vieta’s formulas, we find that the root is \( d - c \).
Final Answer:
\[
\boxed{d - c}
\]