Answer: (-5, 0)
Step-by-step explanation: The equation is already in completing the square form, a(x-h)^2 + k so you have both the x and y values for the vertex. Since there is no k here, the y value is 0.
 
        
             
        
        
        
Try (2y+1) over Y 
not sure if that’s correct tho
        
             
        
        
        
Felipe subtract 3x from both side to get rid of x on one side. Ik this isn’t part of the answer but the correct way to do this would be to subtract 2x from each side after adding 8 to each side of the equation