2xy-x²-y²
=-(x²-2xy+y²)
=-(x-y)²
(a-1)+b²(1-a)
=(a-1)-b²(a-1)
=(a-1)(1-b²)
=(a-1)(1+b)(1-b)
x的五次方-x
=x(x的4次方-1)
=x(x²-1)(x²+1)
=x(x-1)(x+1)(x²+1)
2xy-x²-y²
=-(x²-2xy+y²)
=-(x-y)²
(a-1)+b²(1-a)
=(a-1)-b²(a-1)
=(a-1)(1-b²)
=(a-1)(1+b)(1-b)
x的五次方-x
=x(x的4次方-1)
=x(x²-1)(x²+1)
=x(x-1)(x+1)(x²+1)