Write the function in vertex form, and identify its vertex. g(x) = 5x2 - 50x + 128

Hello : 
g(x) = 5x² - 50x + 128    
       = 5(x²-10x +128/5)
       = 5 (x²-10x+5²-5² +128/5)
        = 5 ((x-5)² +128/5 -125/5)
y = 5 ((x-5)² - 3/5)
y= 5(x-5)² +3vertex form
the vertex is : (5,3)