题目下列从左边到右边的变形,是因式分解的是（ ）A.(3−x)(3+x)=9−x2\left(3-x\right)\left(3+x\right)=9-x^{2}(3−x)(3+x)=9−x2B.m3−n3=(m−n)(m2+mn+n2)m^{3}-n^{3}=\left(m-n\right)\left(m^{2}+mn+n^{2}\right)m3−n3=(m−n)(m2+mn+n2)C.(y+1)(y−3)=−(3−y)(y+1)\left(y+1\right)\left(y-3\right)=-\left(3-y\right)\left(y+1\right)(y+1)(y−3)=−(3−y)(y+1)D.4yz−2y2z+z=2y(2z−yz)+z4yz-2y^{2}z+z=2y\left(2z-yz\right)+z4yz−2y2z+z=2y(2z−yz)+z知识点：因式分解的应用章节：数与式 / 因式分解
