If the partial merger petition has been approved by the commissioners of the merging district and the merger district and if three-fifths of the qualified electors in the area to be merged sign a petition to merge the districts, no election on the question of the merger is necessary, in which case the auditor or lead auditor shall return the petition, together with a certificate of sufficiency, to the board of the merger district. The board of the merger district shall then adopt a resolution declaring the portion of the district merged in the same manner and to the same effect as if the same had been authorized by an election.