观察下列各式:
(x−1)÷(x−1)=1;
(x2−1)÷(x−1)=x+1;
(x3−1)÷(x−1)=x2+x+1;
(x4−1)÷(x−1)=x3+x2+x+1;
…
(x8−1)÷(x−1)=x7+x6+x5+⋯+x+1.
(1)根据上面各式的规律填空:
①(x2023−1)÷(x−1)=________________________;
②(xn−1)÷(x−1)(n为正整数)=______________________.
(2)利用(1)中②的结论求22020+22019+⋯+2+1的值.
(3)若1+x+x2+⋯+x2021=0,求x2022的值.