precalculus
posted by suie .
x^3e^x  4e^x =0

e^x (x^3  4) = 0
e^x = 0
x = oo
x^3 = 4
x = 4^(.333....)
Not sure if you do complex arithmetic
360/3 = 120
if so you also have two complex roots
one at +120 degrees and one at  120
x = r (cos 120 + i sin 120)
x = 4^(1/3) ( .5 + i sqrt3/2)
x = 4^.3333...(.5)(1+isqrt 3)
and the other is
x = 4^.3333...(.5)(1isqrt 3) 
but the answers are 0,2,2

If the equation is as you typed my money is riding with Damon.
Your answers don't even come close to satisfying the equation. 
are u sure b/c the answers are from the book