parabola help

[memeningful]

I would like some help with this parabola

[Shadowxo]

So you have 2 points from the graph: (2.5 ,0), (4,0), (5, 2.5)
Just substitute these x and y values into y=ax^2+bx+c, and you'll have 3 equations you can solve. I'd recommend using solving by elimination but you could also use substitution.