I have a 2006 chevy trailblazer and it has 235 65 17 on it and i found a good price on 225 50 17 will these w?

YES the new tire is a bit narrower, less tall but the same rim size. it may throw the odometer of by a few miles an hour above 59mph but should wirk fine. you will lose about a half inch ground clearance, maybe less from a smaller tire.lowering the center of gravity slightly will improve stability and handling so thats a good thing. If you have any air monitoring systems or abs brakes talk to a shop manager and ask him if this would change anything important.