题目下列从左到右的等式变形是不是因式分解?如果不是,请说明理由.(1)a2−2a+1=a(a−2)+1(1)a^{2}-2a+1=a\left(a-2\right)+1(1)a2−2a+1=a(a−2)+1；(2)(x−1)(x+6)=x2+5x−6(2)\left(x-1\right)\left(x+6\right)=x^{2}+5x-6(2)(x−1)(x+6)=x2+5x−6；(3)x3−x=x(x+1)(x−1)(3)x^{3}-x=x\left(x+1\right)\left(x-1\right)(3)x3−x=x(x+1)(x−1)；(4)m+4=m(1+4m)(4)m+4=m(1+\frac{4}{m})(4)m+4=m(1+m4).知识点：因式分解的应用章节：数与式 / 因式分解
