Find the constant term for each of the following:
P(x)=(x-2)(x-3)(x+7)
P(x)=(x+2)(x-3)(x+7)
P(x)=.5(x-2)(x-3)(x+7)
P(x)=5(x-2)(x-3)(x+7)
P(x)=-5(x-2)(x-3)(x+7)