Solution - Polynomial root calculator
x=-1.628822
x=0.399107
x=9.229716
Step-by-step explanation
1. Normalize to P(x)=0
Rewrite in standard form P(x)=0, then identify the leading and constant coefficients.
2. Test candidate roots
Build rational candidates from factor ratios p/q: -1, 1, -2, 2, -3, 3, -6, 6. Evaluate P(c) for each candidate and deflate when P(c)=0.
3. Solve the remaining factor
After deflation, solve the remaining factor using numeric approximation (Durand-Kerner).
4. Collect all roots
All roots with multiplicity: x={-1.628822,0.399107,9.229716}.