题目下列各式分解因式正确的是（ ）A.x3−x=x(x2−1)x^{3}-x=x(x^{2}-1)x3−x=x(x2−1)B.x2−4x=x(x−4)x^{2}-4x=x\left(x-4\right)x2−4x=x(x−4)C.(a+4)(a−4)=a2−16(a+4)\left(a-4\right)=a^{2}-16(a+4)(a−4)=a2−16D.x2+y2=(x+y)(x−y)x^{2}+y^{2}=\left(x+y\right)\left(x-y\right)x2+y2=(x+y)(x−y)知识点：提公因式法、运用公式法章节：第17章 因式分解 / 17.1 用提公因式法分解因式
