The expression that should be added to the polynomial f(x) = x4 + 2x3 – 2x2 + x + 1, so that it should be exactly divisible by (x2 + 2x – 3) is
The expression that should be subtracted from the polynomial f(x) = x4 + 2x3 -13x2 - 12x + 21 so that the resulting polynomial is exactly divisible by g(x) = x2 – 4x + 3 is