The equation of a parabola is the following:
[tex](y - k) = a(x - h)^{2}[/tex]
where [tex](h, k)[/tex] is the coordinate of the vertex and [tex]a[/tex] is a constant. With the information you have above, you are able to fill in [tex](h, k)[/tex] and solve for [tex]a[/tex] with the information that [tex](1, 0)[/tex] and [tex](5, 0)[/tex] are roots of the equation.