Question

HELPPPP!!!! CALCULAȚI SUMELE!!!! b,c ȘI d!!!!!!
VĂ ROG!!!!! COROANĂ+PUNCTE!!!!!

Answer 1

Este suma lui Gauss cu pas(din x in x)

b) S=11+22+33+...+110+121

S=121+110+99+...+22+11

(Linie)

2S=132+132+132+...+132+132

(121-11):11+1=111:11+1=9+1=10

2S=132×10/:2

S=132×10:2=>S=132×5×2:2=>S=132×5=660

c) S=111+222+333+...+999

S=999+888+777+...+111

(linie de adunare)(+)

2S=1000+1000+1000+...+1000

(999-111):111+1=888:111+1=8+2=10

2S=999×10/:2

S=999+10:2=>S=132×10×2:2=>S=132×10=1320

d) S=5+10+15+...+845+850

S=850+845+840+...+5

2S=855+855+855+...+855

(linie de adunare)(+)

2S=(850-5):5+1=845:5+1=169+1=170

2S=850×170/:1

S=850×170:2=>S=850×170×2:2=>S=850×170=144500