Question

sa se calculeze (a+b+c)(a^2+b^2+c^2-ab-ac-bc) unde a=-1 ; b= 0 si c= 1

Answer 1

(a+b+c)(a^2+b^2+c^2-ab-ac-bc)=
=(-1+0+1)[-1^2+0^2+1^2-(-1*0)-(-1*1)-0*1]=
=0*(-1+0+1+0+1-0)=0

Answer 2

inlocuim in relatie: (-1+0+1)(1+0+1-0-1-0)=0*1=0
a^2=-1^2=1
b^2=0^2=0
c^2=1^2=1
-ab=-(-1)*0=0
-ac=-(-1)*1=1
-bc=0*1=0