Well I believe you are missing the zeros... But lets explain the generic case
Suppose you have n number of zeros ..... z1, z2, z3, z4.....zn-1,zn
These are the roots of an nth order polynomial
an.x**n +an-1.x**n-1 +.....a2 x**2 + a1.x**1 + a0 = 0
This means that xn = zn , xn-1 = zn-1 , .........x1 = z1
The equation is obtained by multiplying
(x-zn)*(x-zn-1)*......*(x-z2)*(x-z1) = 0
For example, imagine the given zeros z1 =3, z2 = 2
the equation would be ......(x-3)*(x-2) = 0 ........==> x**2 -5x +6 = 0