1. The problem statement, all variables and given/known data 1 + 2 + 2^2 + 2^3 + ...+2^(n-1) = 2^n - 1 2. Relevant equations Sum formula? 3. The attempt at a solution I know you are suppose to use the base case and prove its true for k +1, but I'm not sure what to do for similar bases. Can someone please solve it step by step? Thanks!