Question

calculati . (2+4+......+200)+[(4+8+.....+100)+13]​

Answer 1

Răspuns:

Explicație pas cu pas:

folosim formula sumei lui Gauss

1+2+3+4+5+6+7+...+n=nx(n+1)/2

2+4+6+8+...+200=2(1+2+3+...+100)=2x100x101/2=100x101=10100

4+8+...+100=4(1+2+...+25)=4x25x26/2=1300

(2+4+......+200)+[(4+8+.....+100)+13]​=10100+1300+13=11413