You do not provide the important details. Its not as simple as who owns what percentage. Is this business a partnership? Incorporated corporation or an LLC? If there is a partnership agreement, what does it say about voting/decision making? If an LLC, what does the operating agreement say? If an incorporated business, what do the bylaws say?
Do you get to vote in the company? Decisions like this are not made in a vacuum. There has to be a meeting and a decision made.
Bottom line though, assuming that you can each vote and that the weight of your vote is equal to the percentage in ownership, then whatever your partner says will be the decision because he owns 55%.
However, most agreements are not set up this way though. There should be 3 people in the organization who can vote with each casting one vote. You need 3 to prevent any ties. In such case, 2 votes on any issue will prevail.
