Question 1068323
I'm assuming you're looking for a polynomial with real coefficients.
Complex roots come in complex conjugate pairs for polynomials with real coefficients.
{{{f(x)=a(x-i)(x+i)(x-3i)(x+3i)}}}
{{{f(x)=a(x^2+1)(x^2+9)}}}
{{{f(-1)=a((-1)^2+1)((-1)^2+9)=20}}}
{{{a(1+1)(1+9)=20}}}
{{{a(2)(10)=20}}}
{{{20a=20}}}
{{{a=1}}}
So,
{{{f(x)=(x^2+1)(x^2+9)}}}