من المعادلة:
bold italic x to the power of bold 2 bold space bold space bold plus bold 8 bold italic x bold plus bold 7 bold equals bold 0
نجد أن قيمة bold italic a (معامل begin mathsize 14px style bold italic x to the power of bold 2 end style ) يساوي:
begin mathsize 14px style bold 1 end style
begin mathsize 14px style bold 2 end style
bold 3
bold 4