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Rezolvati:
a)x la a 2-x-12
b)x la a 2 -3x-4
c)x la a 2+4x-5
d)x la a 2-8x-20
e)x la a 2+2x-3
f)x la a 2-x-2



Răspuns :

a)x²-x-12 =x²-4x+3x-12 =x(x-4)+3(x-4)=(x-4)(x+3)
b)x² -3x-4=x²-4x+x-4 =x(x-4)+(x-4)=(x-4)(x+1)
c)x²+4x-5=x²-x+5x-5 =x(x-1)+5(x-1)=(x-1)(x+5)
d)x²-8x-20=x²-10x+2x-20 =x(x-10)+2(x-10)=(x-10)(x+2)
e)x²+2x-3=x²-x+3x-3 =x(x-1)+3(x-1)=(x-1)(x+3)
f)x²-x-2=x²-2x+x-2 =x(x-2)+(x-2)=(x-2)(x+1)