Răspuns :
(21x³ - 14x² + 7x) : (-7x) + (x+1)(x+2)=21x³ : (-7x) - 14x² : (-7x) + 7x : (-7x) + x² + +3x + 2= -3x² + 2x - 1 + x² +3x + 2= -2x² +5x +1
7x (3x la a 2-a - 2x + 1) : (-7x) + (x+1)=
-3x la a 2-a +2x -1 +x +1 =
-2x la a 2-a +2x =
2x (1-x)
-3x la a 2-a +2x -1 +x +1 =
-2x la a 2-a +2x =
2x (1-x)