Răspunsuri

2014-07-08T12:14:34+03:00
2(x² +2x+1)-3(x²-4)+5x²-15x-(9x²-6x+1)=

=2x² +4x+2 -3x²+12 +5x²-15x -9x²+6x+1=

=7x²-12x² +10x +15=

= -5x² +10x +15=

= -5(x²-2x+3)