Question

Efectuati, respectand ordinea efectuarii operatiilor:
(x-2)(x²+3x-1)-(-x)²(1-2x)+x(2x+3)=

Answer 1

(x-2)(x²+3x-1)-(-x²)(1-2x)+x(2x+3)
=x³+3x²-x-2x²-6x+2+x²(1-2x)+2x²+3x
=x³+3x²-x-2x²-6x+2+x²-2x³+2x²+3x
=-x³+4x²-4x+2
-x³+4x²-4x+2=0
D(2)={±1,±2}
| x³ x² x¹ x°
| -1 4 -4 2
-----------------------
1 | -1 3 -1 1
-1 | -1 5 -9 11
2 | -1 2 0 =>x=0
=>-x²+2x=0