Question

determinati fractia zecimala x ,stiind ca media aritmetica a numerelor 9 si x este egala cu 7,8 (3); si 5,2(7)​

Answer 1

Răspuns:

(9+x)/2=7,8(3)

9+x=7,8(3)·2

x=15,(6)-9

x=6,(6)

__________

(9+x)/2=5,2(7)

9+x=5,2(7)·2

x=10,(5)-9

x=1,(5)