Răspuns:
115+(115+2)+...+(115+888)+(115+890)+(115+892)=250767
Explicație pas cu pas:
115+115+2+....+115+888+115+890+115+892 sunt892÷2=446 termeni,factor comun 115×(446+1)+2×(1+2+....+446)= 115×447+2(((446+1)×446)÷2)=51405+2×(447×223)=51405+199362=250767
