If the roots are 1 and 3, the factors of this quadratic are (x-1) and (x-3).
The polynomial is x^2 - 4x + 3.
If you were supposed to write a polynomial based upon all four given roots, then:
Looks as tho' you have four distinct roots. The 4th order polynomial with these roots is f(x) = (x-1)(x-3)(x-7)(x-2). Multiply this out, combine like terms and then arrange the terms in descending order by powers of x.
