Question

CALCULATÍ URMATOARELE SUME DE NR. NATURALE
a) 1+ 2+ +25=
b) 1+ 2+ +50=
c) 1+ 27.-- +200 =
d) 1+2+...+36=​

Answer 1

Răspuns:

a)325

b)1275

c)20100

d)666

Explicație pas cu pas:

presupun ca is .... intre ele si e vb de Gauss

a) =[(25+1)*(25-1+1)]:2= 650:2= 325

b) =[(50+1)*(50-1+1)]:2=2550:2=1275

c)[(200+1)*(200-1+1)]:2=40200:2=20100

d)[(36+1)*(36-1+1)]:2=1332:2=666

Answer 2

a) 28
b) 53
c) 1+27+200= 228
d) 55