>符号中为几次方x-3px+(3p-q)x-p(p-q)

x^3-3px^2+(3p^2-q^2)x-p(p^2-q^2)=x^3-3px^2+2p^2x+(p^2-q^2)x-p(p^2-q^2)=(x^2-3px+2p^2)x+(x-p)(p^2-q^2)=(x-2p)(x-p)x+(x-p)(p^2-q^2)=(x^2-2px)(x-p)+(x-p)(p^2-q^2)=(x-p)(x^2-2px+p^2-q^2)=(x-p)[(x-p)^2-q^2...