Răspuns :
2+4+6+...+100=2•(1+2+3+...+50)
1+2+3+...+50=[50•(50-1)]:2=(50•49):2=2450:2=1225
2+4+6+...+100=2•1225=2450
Sper ca te-am ajutat
1+2+3+...+50=[50•(50-1)]:2=(50•49):2=2450:2=1225
2+4+6+...+100=2•1225=2450
Sper ca te-am ajutat