Question 1127878
Rational Roots theorem will give several possible roots to check.  You could expect that -4 and -5 will be roots.  Try checking these using synthetic division and see what you find!


-4, ---------------   1, 5, 9, 45, 0


-5, --------------  1, 0, 9, 0


{{{f(x)=(x+4)(x+5)(x^2+9)}}}