Question

Aflati numarul X din agalitate 1+3+5+.....+99+X=2+4+6+.....+100=?​

Answer 1

Răspuns:

1+3+5+..+99+x=100x50/2+x=50x50+x=2500+x

2+4+6+..+100=2(1+2+3+..50)=2((50x51):2)=2x1275=2550

2500+x=2550

x=2550-2500

x=50