Question

(x+y)(x²-xy+y²),(x-y)(x²+xy+y²)

Answer 1

(1)

(x+y)(x²-xy+y²)=x^3+y^3

(x-y)(x²+xy+y²)=x^3-y^3

可以用于三次方和差的因式分解公式

(2)

①a^3+8b^3

= a^3+(2b)^3

=(a+2b)(a^2-2ab+4b^2)

②m^6-1

=(m^3+1)(m^3-1)

=(m+1)(m^2-m+1)(m-1)(m^2+m+1)