a) P(1) =1-4+a+b = -3 de unde a+b=-3+3=0 P(-1)=-1-4-a+b =7 de unde -a+b=7+5=12 adunand cele doua relatii vom avea 2b=12 b=12/2 b=6 a+6=0 a= -6 b) P(x) +9x-6= x³-4x²-6x+6+9x-6=x³-4x²+3x= x³-x²-3x²+3x=x²(x-1)-3x(x-1)=(x-1)(x²-3x)=(x-1)x(x-3)=x(x-1)(x-3)
