Consider the polynomial x^3 + 6x^2 + 3x - 10. Without dividing, or graphing, which two of (x+2), (x-2), (x+1), and (x-1) must be factors of the polynomial? Why/how do you know?

I will need a 5 and a 2 to make 10

I need 2+5-1 to make 6 x^2
that leaves a (x+2)(x+5)(x-1)
so I think
(x+2) and (x-1)