Is my solution correct?
Question: Find all z, such that (z+1)7=z7.
My answer: Since z≠0, we can divide by z7 on both sides to get (z+1z)7=1. If we let w=z+1z, then w is equal to the 7th roots of unity. We can manipulate w=z+1z by multiplying both sides by z, then subtracting z from both sides to get 1=zw−z. We can then divide both sides by w−1 to get z=1w−1.
The seven roots of unity are 1, e2iπ7, e4iπ7, e6iπ7, e−6iπ7, e−4iπ7, e−2iπ7. z=11−1 if w=1 is not defined, and we can see that it doesn't work for (z+1)7=z7, either, so the solutions for z are 1e2iπ7−1, 1e4iπ7−1, 1e6iπ7−1, 1e−6iπ7−1, 1e−4iπ7−1, and 1e−2iπ7−1, respectively.