Răspunsuri

2014-05-13T20:24:40+03:00
X²+6x+9+2(x²+3x-4x-12)+x²-8x-16
x²+6x+9+2x²+6x-8x-24+x²-8x+16
4x²-4x+1=(2x-1)²
1 5 1