Which two values of x are roots of the polynomial below? x2 + 3x + 5

Your polynomial is a quadratic, a second degree polynomial, to be exact.  It can be factored to solve for those values of x you are looking for.  Depending upon how you're factoring in class, solving can be done 1 of several ways but the never-fail way is the quadratic formula.  Putting those values into the quadratic formula gives us this:   which simplifies to  .  We have to deal with the square root of -11 now.  Rewriting using the imaginary i gives us  .  Since -1 is equal to i^2, we can make that replacement in our formula:  .  We can now pull out a single i from the i^2 and write the answer in standard form.  .  .    Standard form is  .  There you go!