Question

Decat 5. Va rog, daca se poate cat mai repede.

Answer 1

^3-inseamna,la,puterea,a,treia

E(1)=(1/2)^3(1+2+1)=1/8x4=1/2
E(2)=(2/3)^3(1/4+2/8+1/16)=8/27x9/16=1/6
E(3)=(3/4)^3(1/9+2/27+1/81)=27/64X16/81=1/12

E(1)+E(2)+E(3)=1/2+1/6+1/12
Aducem,la,acelasi,numitor(12),si,avem
6/12+2/12+1/12=9/12=3/4