Răspuns:
Explicație pas cu pas:
a)=1/101(1+2+...+100=100×101/2·101=200
b)=1/117(1+2+....+99)=99·100/2·117=11·50/13=550/13
c)1/303(1+2+....+251)-1/303(1+2+...+51)=
=251·252/2·303-51·52/303·2=1/303(251·126-51·26)=(31606-1326)/303=
=30280/303
e)99×100/4·125=99/5
f)100·101/4·255=25·101/255=505/51
