Question

Calculati: a) 3+7+11+15+19+23 b) suma primelor 100 de numere naturale impare. c) suma primelor 100 de numere pare. Dau coroana am nevoie de ajutor urgent!!

Answer 1

a)68
b)    O suma =1+3+5+...+101
    Alta suma =101 + 99 + 97+...+1
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2Sume=102+102+102+...+102

Nr de elemnte = (101-1):2 = 100:2 = 50 termeni

2Sume = 50*102 =  5100
c)

   O suma =2+4+6+...+100
Alta suma =100 + 98 + 96+...+2
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2Sume=102+102+102+...+102

Nr de elemnte = (100-2):2 = 98:2 = 49 termeni

2Sume = 49*102 =  4998
O suma = 4998:2 = 2499

Sper ca ti-am fost de ajutor

Answer 2

a)3+7+11+15+19+23=78
10+11+15+19+23=
21+15+19+23=
36+19+23=
55+23=78
b)1+3+5+7+9+11+13+15+16+17+19+21+23+25+27+29+31+33+35+37+39+41+43+45+47+49+51+53+55+57+59+61+63+65+67+69+71+73+75+77+79+81+83+85+87+89+91+93+95+97+99=2500 />c)0+2+4+6+8+10+12+14+16+18+20+22+24+26+28+30+32+34+36+38+40+42+44+46+48+50+52+54+56+58+60+62+64+66+68+70+72+74+76+78+80+82+84+86+88+90+92+94+96+98+100=2550