m²-4n²+2m-4n
=(m+2n)(m-2n)+2(m-2n)
=(m+2n+2)(m-2n)
x²-2xy+y²+ax-ay
=(x-y)²+a(x-y)
=(x-y+a)(x-y)a²-b²+2a+1 因式分解a²-b²+2a+1=a²+2a+1-b²=(a+1)²-b²=(a+1+b)(a+1-b) 帮忙采纳3a²—3ab+2ab-2b²-a+b 因式分解采纳后，重新提问。