$a, b, c$ are in AP $E=\frac{a+8b}{2b-a} + \frac{8b+c}{2b-c}$ then possible value of $E^2$ 
$a, b, c$ are in AP $E=\frac{a+8b}{2b-a} + \frac{8b+c}{2b-c}$ then possible value of $E^2$ is? 
  
  
*
  
*256
  
*225 
  
*361
  
*320
  

I plugged in $b=\frac{a+c}{2}$ to get $$E=4+ 5\frac a c + 5\frac c a$$ 
I do not know how to proceed from here

By Am-Gm inequality we have $${a\over c}+{c \over a}\geq 2\sqrt{{a\over c}\cdot{c \over a}} =2$$ so we have $E\geq 18$ and thus $$E^2\geq 324$$ So the answer is third option.
