If the polynomial has integer coefficients, its complex or radical roots come in conjugate pairs. That is, -√10 is also a root. The four roots mean the polynomial has degree 4. That eliminates all but answer choice C.
Each root 'a' gives rise to a factor (x -a), so the factored polynomial is ...
You didn't write the (-2/7) as a power; you were supposed to do b to the power of -2 over 7, which is what the other person done in your other post regarding this
