Answer:
(a-1) *(a^2 +a-1) (a+2)
Step-by-step explanation:
a^4+2a^3-a-2
Lets factor by grouping
a^4-a + 2a^3-2
Factor out an a from the first group and a 2 from the second group
a(a^3 -1) +2(a^3-1)
Factor out (a^3-1)
(a^3-1)(a+2)
We need to recognize that a^3-1 is the difference of cubes
(x^3-y^3) = (x-y) (x^2+xy+y^2)
Let x=a and y=1
(a-1) *(a^2 +a-1) (a+2)
