Written notice of each meeting of shareholders shall be given to each shareholder of record entitled to vote at the meeting at least five days prior to the date thereof, unless a longer period of notice is required by the articles, by-laws or other provisions of this act. Notice of an adjourned meeting and of the business to be transacted at such meeting may be given by announcement at the meeting at which the adjournment is taken unless otherwise provided in the articles or by-laws.