Question 921560
Multiplicity of 2 must be for the root -3.  Complex roots with imaginary parts come as conjugate pair.


{{{f(x)=(x-(-5-2i))(x-(-5+2i))(x-(-3))^2}}}
Work with that.   Simplify in whatever form you need.  Be sure to notice and take advantage of Difference of Square...


Skipping the showing of most of the steps, you should find these:

{{{((x+5)^2+4)(x+3)^2}}}

{{{highlight((x^2+10x+29)(x+3)^2)}}}, here kept still in the factored form.