Zeros: x=1 (multiplicity 2) and x=-4

Starting with x=1, subtract 1 from each side,

(x-1) = 0

Our polynomial will have multiplicity of 2 for this particular zero,

(x-1) (x-1)

and do similar with the x=-4, add 4 to each side,

(x+4) = 0

So our final result is: (x-1) (x-1) (x+4)

Expand out the brackets if you need this in standard form.