Answer:
x – 5 and x + 3
Step-by-step explanation:
Knowing that x + 4 is a factor, we can use grouping to factor:
x³ + 2x² – 23x – 60
x³ + 2x² – 8x – 15x – 60
x (x² + 2x – 8) – 15 (x + 4)
x (x – 2) (x + 4) – 15 (x + 4)
(x (x – 2) – 15) (x + 4)
(x² – 2x – 15) (x + 4)
(x – 5) (x + 3) (x + 4)
To use long division, see attached image.
