Find the roots of the equation

Question

Find the roots

x^3 + x^2 = 7x + 15

then

given the zeros, write a polynomial function of least degree with integral coefficients

-3 (multiplicity of 2), root 5

Answer 1

A possible rational root is 3 (it divides 15)

Dividing out (x-3) gives x² +4x + 5 which has no real roots (i.e. 3 is a root and there are 2 complex roots.)

I do not understand what is being required in the 2nd part of the problem.