Question

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Answer 1

Răspuns:

Aplici  formulaA³-B³=(A-B)(A²+AB+B²)  unde

A=(x+1)  

b=(x-2)

(x+1)³-(x-2)³=

[(x+1-(x-2)]*[(x+1)²+(x-2)(x+1)+(x-2)²]=9

(x+1-x+2)*(x²+2x+1+(x²-2x+x-2)+x²-4x+4)=9

3[x²+2x+1+(x²-x-2)+x²-4x+4]=9:║:3

x²+2x+1+x²-x-2+x²-4x+4=3

3x²-3x+3=3

3x²-3x=0

3x(x-1)=0

x1=0

x2=1

ecuatia  nu  are  solutii  reale

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