Question 581225
You can cancel out the x-s only when they are factors. In our case the denominator is x+2 and the nominator x+8, are different factors.
Suppose that x=2 then:

{{{(x+8)/(x+2)=(2+8)/(2+2)=10/4}}} (right)

{{{ (x+8)/(x+2)=(2+8)/(2+2)=8/2=4}}} (wrong)