By separating out the term with index k=0, we can now write each of the power series from the expression with an index that starts at k=1 and start with the same power ofx.k=07(k+1)ck+1xk=7c1+ k=17(k+1)ck+1xk k=16ck-1xkTo finish, rewrite the given expression using a single power series whose general term involves xk.7ncnxn-1n=1 + 6cnxn+1n=0 + k=1