we have that
(14x2 - 3x3 + 9x4) - (-14 + 13x3 + 11x4)=14x2 - 3x3 + 9x4 +14 - 13x3 - 11x4
(14x2 - 16x3 +14 - 2x4)
then
-2x4-16x3+14x2+14=0--------------> this is the standard form
simplify dividing the entire expression by two
-x4-8x3+7x2+7=0
the answer is
-x4-8x3+7x2+7=0