Answer:
1 and -2 (has a multiplicity of 2)
Step-by-step explanation:
so since x=-2 is a root then (x+2) is a factor of the polynomial. This means you can divide the polynomial by (x+2) by using synthetic or long division. So for this example I'll using synthetic division which is much more simple than long division
-2 | 1 3 0 -4
-2 -2 4
1 1 -2 0
(x+2)(x²+x-2)
Now you can factor the quadratic into
(x+2)(x-1)
x+2 = 0
x = - 2
x-1 =0
x = 1
