(a) Unless the articles of incorporation or bylaws require a greater number or unless otherwise specifically provided in this Act, a quorum of a board of directors consists of a majority of the number of directors specified in the articles of incorporation or bylaws.

(b) If a quorum is present when a vote is taken, the affirmative vote of a majority of directors present is the act of the board of directors unless the articles of incorporation or bylaws require the vote of a greater number of directors.