Simply replace each x with the given value of x.
When x = -2:
[tex]8(-2)^3\\8(-8)\\\\=-64[/tex]
When x = -1:
[tex]8(-1)^3\\8(-1)\\\\=-8[/tex]
When x = 0:
[tex]8(0)^3\\8(0)\\\\=0[/tex]
When x = 3:
[tex]8(3)^3\\8(27)\\\\=216[/tex]
OR you could use a graph for this, here is how the function is going to look: