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BlackFirew
a fost răspuns

Calculati : (3x-1)^3+(3x=1)^3
As vrea si formula de calcul daca se poate, multumesc.

Răspuns :

Rayzen

(3x-1)³ + (3x+1)³ =

= [(3x-1)+(3x+1)]·[(3x-1)² - (3x-1)(3x+1) + (3x+1)²] =

= (6x)·[(3x-1)² - (9x²-1²) + (3x+1)²] =

= (6x)·(9x²-6x+1-9x²+1+9x²+6x+1) =

= 6x·(9x²+3)

Am folosit formula de calcul prescurtat:

a³ + b³ = (a+b)·(a²-ab+b²)

Alte intrebari