Answer
$f(x)=3(x+3)(x-1)(x-4)$
Work Step by Step
If $a$ is a zero of a function with multiplicity $b$ then $(x-a)^b$ is a “multiplier” of the function.
Hence here $f(x)=k(x+3)(x-1)(x-4)$
$(0,36)$ (because of the y-intercept) is on the graph thus $k\cdot(3)(-1)(-4)=36\\12k=36\\k=3$
So $f(x)=3(x+3)(x-1)(x-4)$
