Question

ia sa vedem cine cade in plasa...

Answer 1

numere din 3 in 3 
x · 1 /3 [  1/1 - 1/4 + 1/4 - 1/7 +1/7  - 1/10 + 1/10  - 1/13 ] =3 /26 
x · 1 /3 [ 1 -   1 /13 ]   =  3/26 
 x · [ 12 /13  ] =   3· 3 /26 
x · 12 = 13· 3· 3 /26 
x = 9 /24 

Answer 2

x(1/4+1/4*7+1/7*10+1/10*13)=3/26
x(455+65+26+14)/1820=3/26
x(455+65+26+14)/1820=3/26
560x/1820=3/26
20x/65=3/26
x=65*3/20*26=195/520=39/104=3/8=0,375