Question

calculați:
a)2+4+6+...+200
b)1+3+5+7+...+197
c)(1+2+3+4+...+195):5
ajtorrr
*dau coroană*:)))

Answer 1

2(1+2+3+......+100)=2x100x101/2=10100

1+3+5+7+......+197 aflam nr.de termeni  (197-1):2+1=99 termeni
S=99*198/2
S=99*98
S=9702

(1+2+3+........+195)5=195*196/2:5=39*98=3822