Question

What are all of the real roots of the following polynomial f(X)=x5+3x4+5x3+15x2+4x+12

Answer 1

See below.

Explanation:

f(X) =x5+3x4+5x3+15x2+4x+12

=x5+12+15+30+4x+12

=(x5+4x)+(12+15+30+12)

=9x+69