常见 因式分解
公式:
(x+a)(x+b)=x2+(a+b)x+ab
(a±b)2=a2±2ab+b2
(a±b)3=a3±3a2b+3ab2±b3
a2−b2=(a−b)(a+b)
a3−b3=(a−b)(a2+ab+b2)
a3+b3=(a+b)(a2−ab+b2)
(a+b+c)2=a2+b2+c2+2ab+2bc+2ca
a3+b3+c3−3abc=(a+b+c)(a2+b2+c2−ab−bc−ca)
an−bn=(a−b)(an−1+an−2b+an−3b2+⋯+abn−2+bn−1)(n∈Z+)
an+bn=(a+b)(an−1−an−2b+an−3b2−⋯−abn−2+bn−1)(n is odd )