Răspunsuri

2014-06-13T21:21:16+03:00

E(x)=[3(4x-2)-(x-6)][3(4x-2)+(x-6)]
E(x)=(12x-6-x+6)(12x-6+x-6)=11x(13x-12)
de unde 3?
pai formula este (a^2-b^2)=(a-b)(a+b) si daca primul este la patrat cad e fara 9 devine 3
adica radical din 9(4x-2)^2=3(4x-2)
2014-06-13T21:26:35+03:00
9(4x-2)la a 2-(x+6) la a 2
9(16x^2-16x+4)-(x^2+12x+36)=
144x^2-144x+36-x^2-12x-36=
143x^2-156x=
x(143x-156)