1、
2a^2+4ab+2b^-8
=2(a^2+2ab+b^2-4)
=2[(a^2+2ab+b^2)-4]
=2[(a+b)^2-2^2]
=2*(a+b+2)*(a+b-2)
2、
(1/2)x^2+2xy+2y^4
——后面是y^4吗?!个人觉得应该是y^2!
3、
x^2-y^2+2y-1
=x^2-(y^2-2y+1)
=x^2-(y-1)^2
=(x+y-1)*(x-y+1)
1、
2a^2+4ab+2b^-8
=2(a^2+2ab+b^2-4)
=2[(a^2+2ab+b^2)-4]
=2[(a+b)^2-2^2]
=2*(a+b+2)*(a+b-2)
2、
(1/2)x^2+2xy+2y^4
——后面是y^4吗?!个人觉得应该是y^2!
3、
x^2-y^2+2y-1
=x^2-(y^2-2y+1)
=x^2-(y-1)^2
=(x+y-1)*(x-y+1)