1-x^2+2xy-y^2=1-(x-y)^2=(1+x-y)(1-x+y)
多项式ax^2-4a与x^2-4x+4的公因式是x-2
ax^2-4a=a(x+2)(x-2)
x^2-4x+4=(x-2)^2
x^2-y^2-x-y=(x+y)(x-y)-(x+y)=(x+y)(x-y-1)1.若(a+4)^2+(4b-1)^2=0,则a^2008×b^2009=2.(3m+2n)^2-4(m-n)^2分解因式 能说详细点吗谢谢1)(a+4)^2+(4b-1)^2=0(a+4)^2>=0(4b-1)^2>=0所以a+4=04b-1=0a=-4 b=1/4a^2008×b^2009=(ab)^2008*b=(-1)^2008*1/4=1/42)(3m+2n)^2-4(m-n)^2=9m^2+12mn+4n^2-4m^2+8mn-4n^2=5m^2+20mn=5m(m+4n)