Hi Katy

According to the factor theorem,

For a polynomial P(x), x - a is a factor if P(a) = 0.

therefore substituting x=1 in the polynomial

P(x) =(x^3+3x^2+13x-15)

P(1) = 1+3+13-15

=2

again substituting x=2 in P(x)

P(2)= 8+12+26-15

=31

P(3)=27+27+39-15

=93

As the remainder is not zero for x=1,2,3,4,.............so on

Hence the given polynomial P(x) =(x^3+3x^2+13x-15)

has no factor

I think the polynomial u have given is unfactorizable