Question

am nevoie de ajutor ex . 23 si 24 dau coroana

Answer 1

23.) a.) -21/10+(1/4-1/5+1/5-1/6+1/6-1/7+...+1/39-1/40=-21+(1/4-1/40)=-21/10+9/40=-75/40
b.) -7/16+(1/8-1/9+1/9-1/10+1/10-1/11+...+1/47-1/48)=-7/16+5/48=-16/48
c.) -96/90+(1/5-1/6+1/6-1/7+1/7-1/8+...+1/44-1/45)=-96/90+8/45=-80/90
24.) a.)(1/2-1/3+1/3-1/4+1/4-1/5+...+1/63-1/64)+(-75/128)=(1/2-1/64)+(-75/128)=31/64-75/128=-13/128
b.) 1/2012+(1/1-1/2+1/2-1/3+1/3-1/4+...+1/2011-1/2012)=1/2012+(1/1-1/2012)=1/2012+2011/2012=2012/2012
c.) (1/1-1/3+1/3-1/5+1/5-1/7+...+1/73-1/75)+(1/1-1/2+1/2-1/3+1/3-1/4+...+1/74-1/75)=(1/1-1/75)+(1/1-1/75)=74/75+74/75=148/75
d.) (1/1-1/4+1/4-1/7-1/10+...+1/97-1/100)+(1/20-1/21+1/21-1/22+...+1/79-1/80)=(1/1-1/100)+(1/20-1/80)=99/100+3/80=411/400