a) x³-3x²+x-9 x²
-x³ x-3
= -3x²+x-9
3x²
= x-9
daca folosim teorema impartiri cu rest
x³-3x²+x-9=x²(x-3)+x-9
b) 2x³-x²-4 x³-x
-2x³+2x 2
= -x²+2x-4
2x³-x²-4=2(x³-x)-x²+2x-4
c)-5x³+x²-x+4 x³+1
5x³+5 -5
=x²-x+9
-5x³+x²-x+4=-5(x³+1)+x²-x+9
d) 2x³+x²+5x+60 x+3
-2x³-6x² 2x²-5x+20
=-5x²+5x+60
5x²+15x
=20x+60
-20x-60
= =
2x³+x²+5x+60=(x+3)(2x²-5x+20)