[질문] 곱셈공식 쉬운거말고 몇개만

(a＋b)2=a2＋2ab＋b2 (a＋b)(a－b)=a2－b2 (a－b)2=a2－2ab＋b2 (a＋b)(a2－ab＋b2)=a3＋b3 (a＋b＋c)2=a2＋b2＋c2＋2ab＋2bc＋2ca (a＋b)3=a3＋3a2b＋3ab2＋b3