Răspuns :

[tex]224+225+226+..+399=[/tex]
=[tex]224+(224+1)+(224+2)+...+(224+175)=[/tex]
=[tex]224*176+(1+2+...+175)=[/tex]
=[tex]39424+175*176:2=39424+15400=54824[/tex]
a)
224 + 225 +...+ 399;
Aflam numarul termenilor:
399 -224 + 1 = 176 termeni
S = (399 + 224) * 176 / 2 = 54824

b)
110+111+...+400;
Aflam numarul termenilor:
400 - 110 + 1 = 291
S = (400 + 110) * 291 / 2 = 74205