Question

aflati un numar real, stiind media aritmetica a jumatatii sale, a sfertului sau si a cincimii sale este 12,(6).​

Answer 1

Răspuns:

(a/2+a/4+a/5)/3=12,(6)

12,(6)=(126-12)/9=114/9=38/3

¹⁰⁾a/2+⁵⁾a/4+⁴⁾a/5=38/3·3

10a/20+5a/20+4a/20=114/3

10a/20+5a/20+4a/20=²⁰⁾38

10a+5a+4a=760

19a=760=>a=760:19=>a=40