(x+5) is a factor of

From the factor theorem, we have

(x + 5) is the factor of f(x) if f(-5) = 0

Here, we have

f(-5) = 2(-5)³ + 9(-5)² – 11(-5) – 30

= -250 + 225 + 55 – 30

= -280 + 280

= 0

Therefore,

(x + 5) is the factor of (2x³ + 9x² – 11x – 30)