Rezolvați


30+34+38...+230=
3+6+9...+741=
18+25+32...+151=
11+12+13...+130=
2+4+6...+142=
1+2+3...+70=
1+2+3...+110=
25+26+27...+90=
1+3+5...+191=
2+3+6...230=

v-a rog sa fie rezolvate mai repede dau coruana





Răspuns :

Poti sa faci asa

30+34+38.............+230=s

230+226+222+......30=s

____________________

260+260+260+......260=2*s

2*s=260*201

2*s=52 260

S=52 260:2

26 130

Poti aplica metoda la toate