Question

[Nguyen vu hoang minh]

Phan tic h da thuc thanh nhan tu

A^3+b^3+c^3-3abc

Answer 1

[OoO_Nhok_Lạnh_Lùng_OoO]

   a^3 + b^3 +c^3 - 3abc 

= ( a + b )^3 - 3ab ( a + b ) + c^3 - 3abc 

= [ ( a + b )^3 + c^3 ] + [ -3ab ( a + b ) - 3abc ] 

= ( a + b + c ) * [ ( a + b )^2 - c*( a + b ) + c^2 ] - 3ab ( a + b + c ) 

= ( a + b + c ) * ( a^2 + 2ab + b^2 - ac - bc + c^2 - 3ab ) 

= (a + b + c) * ( a^2 + b^2 + c^2 - ab - ac - bc )