下列等式从左到右的变形,属于因式分解的是( )
A.a(x﹣y)=ax﹣ay | B.x2+3x+2=x(x+3)+2 |
C.(x+y)(x﹣y)=x2﹣y2 | D.x3﹣x=x(x+1)(x﹣1) |
下列因式分解正确的是( )
A.x2+y2=(x+y)(x+y) | B.x2-y2=(x+y)(x-y) |
C.-x2+y2=(-x+y)(-x-y) | D.-x2-y2=-(x+y)(x-y) |