Explanation:
Using the given zeroes, set up the equation like this :
f(x) = a( x - 1/5)(x+4) sub in the given point(0,4) to calculate 'a'
4 = a ( 0 - 1/5)(0+4)
4 = -4/5a
a = -5
f(x) = - 5 ( x-1/5)(x+4) is your equation....
....re-arrange as necessary to the form desired