Find all the roots of the equation x4 - 2x3 + 14x2 - 18x + 45 = 0 given that 1 + 2i is one of its roots.

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Knowing that 1+2i is a root, you also know that 1-2i is a root, so one quadratic factor is
   (x -1)² -(2i)² = x^2 -2x +5

Long division of the given polynomial by this quadratic gives a quotient of 
  x² +9
which has roots ±3i.

Then all the roots are {-3i, 3i, 1-2i, 1+2i}.

Lol english

29. because you will divide each number of months by 12 to find the number of years. which would mean, 5, 12.5, 16, 45, 50, 72.5. which is crazy. anyhow, i think you find the median in the middle. and yea hope your test goes good