(1) 1/2x^2-32
=1/2(x^2-64)
=1/2(x+8)(x-8)
(2) 50a^2-32
=2(25a^2-16)
=2(5a+4)(5a-4)
(3)x^6-y^6
=x^3*2-y^3*2
=(x^3+y^3)(x^3-y^3)
=(x+y)(x^2-xy+y^2)(x-y)(x^2+xy+y^2)
=(x+y)[(x-y)^2+xy](x-y)[(x+y)^2-xy]
(4)(a-b)^2+2(b-a)+1
=(b-a)^2+2(b-a)+1
=(b-a+1)^2