Question

4+8+6+...+100 va rog mult

Answer 1

4+6+8+10+...+100=2x(2+3+4+5+...+50)=2x(1+2+3+4+...+50-1)=2x(1+2+3+4+...+50)-2=2x(50x51/2)-2=50*51-2=2550-2=2548

S-a folosit formula: 1+2+3+4+...+n=n(n+1)/2, in cazul nostru n=50.

Sper sa va fie de folos