I am asked to show that: 2^(x+1) + 2^(x-1) = 160 can be written as 2.5 * (2^x) =160

Could somebody please show me the steps taken to do this simplification? Since there is an addition, I can't get the rules of indicies to help me. In other questions like this I have always been able to use substitution/factorisation but i can't see a common factor.

Thanks for your help.