Respuesta :

Answer:42R/41

Explanation:

R/2+R=3R/2

1/r=1/(3R/2)+1/R

1/r=2/3R+1/R

1/r=5/3R

5r=3R

r=3R/5

3R/5+3R/2=21R/10

1/r=1/2R+1/2R

1/r=1/R

r=R

R+R=2R

1/r=1/2R +1/(21R/10)

1/r=1/2R+10/21R

1/r=41/42R

41r=42R

r=42R/41