create the equation of a cubic polynomial f(x) that has a double zero at (0,0) a single zero at (-3,0) and that passess through (1,16)

i understand that (x+3) is a factor but how would you find a ... how would you answer this question?? please help this is for my summative i also considered subbing y and x (1,16) into the formula for finding a and all i got in the end was this: f(x)=4x^2(x+3)