There's a trick to know here:
If (a,0) or x=a is an x-intercept, then (x-a) is a factor of the polynomial.
From your graph, you have x=0, x=5, and x=7 as the x-intercepts.
Then (x-0), (x-5), and (x-7) are factors of the polynomial.
(Note: (x-0) would usually be written just as "x".)
So, the factored form is v(x) = x (x-5) (x-7)
