1/2x²-2x+1/2x²+1
=x²-2x+1
=(x-1)²
(1/2x²-2x)+(1/2x²+2x-1)
=x²-1
=(x+1)(x-1)
(1/2x²+1)+(1/2x²+2x-1)
=x²+2x
=x(x+2)