Răspunsuri

2014-11-18T20:55:24+02:00
Folosim formula:
 a^{3} - b^{3} = ( a-b )*( a^{2} + a*b + b^{2} )

 x^{3} - (2x-y)^{3} =
 = [ x - (2x-y)]*( x^{2} + x*(2x-y)+(2x-y)^{2} ]=
 = ( x - 2x+y)*( x^{2} + 2 x^{2} -x*y + 4*x^{2}-4*x*y+ y^{2}  )=
 = ( y-x)*( 7* x^{2} -5*x*y + y^{2}  )

Sper ca nu am gresit la calcule. Daca da, voi corecta.







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