Respuesta :

Answer:

Step-by-step explanation:

Let n = 1. Then:

2 + 22 + 23 + 24 + ... + 2n = 21 = 2

...and:

2n+1 – 2 = 21+1 – 2 = 22 – 2 = 4 – 2 = 2

So (*) works for n = 1.

Assume, for n = k, that (*) holds; that is, that

    2 + 22 + 23 + 24 + ... + 2k = 2k+1 – 2

Let n = k + 1.