@ -62,11 +62,11 @@ $$\text{rank}(A - E) = k$$
(1) ∵ $AB = 2A - B$
$$
\therefore (A - 2E)(B + E) = -2E
\therefore (A + E)(B - 2E) = -2E
\therefore (A - 2E)(B + E) = (B + E)(A - 2E)
\therefore ( B - 2E)(A + E) = (A + E)(B - 2E)