Find a monic quartic polynomial with rational coefficients whose roots include x = 1 - sqrt(2) and x = 2 + sqrt(7).
For a polynomial with rational coefficients, the the irrational roots come in pairs.
If one root is 1 + sqrt(2), the other one must be 1 - sqrt(2).
Similarly, if one root is 2 + sqrt(7), the other one must be 2 - sqrt(7).
Now that the roots are found, you can find the factored form of the quartic. :))