分解因式：x²-4y²-x+2y.

分解因式：x²-4y²-x+2y.
分解因式：x²-4y²-x+2y.

分解因式：x²-4y²-x+2y.
原式=x²-4y²-(x-2y)=(x+2y)(x-2y)-(x-2y)=(x+2y-1)(x-2y)

原式=（x+2y)(x-2y)-(x-2y)
=(x-2y)(x+2y-1)

x²-4y²-x+2y
=x²-x+(1/4)²-[4y²-2y+(1/4)²]
=(x-1/2)²-(2y-1/2)²
=[(x-1/2)+(2y-1/2)][(x-1/2)-(2y-1/2)]
=(x-1/2+2y-1/2)(x-1/2+2y-2y+1/2)
=(x+2y-1)(x-2y)