First factor the numerator
b^2-6b+8/b-4 * b+8/b-2
u will get
(b-2)(b-4)/(b-4)*(b-2)*b+8
those will cancel out each other will left only
b+8<span />
I hope this helps you
x= -1
f (-1)= 2. (-1)^2
f (-1)= 2.1
f (-1)= 2
The last 2 options are correct
if ya asking for simpliicatio
remember that 
and


factor



