Question

trei nr naturale au suma 74 . media aritmetica a primelor doua e 21 iar media aritmetica a ultimelor doua e 28 . aflati cele trei nr . HELP ME !!!!

Answer 1

a+b+c=74
(a+b):2=21=>a+b=42
(b+c):2=28=>b+c=56
________(+)
a+2b+c=98
a+b+c=74=>b=24
a=42-24=18
c=56-24=32
Verificare:24+18+32=24+50=74

Answer 2

[tex]a+b+c=74\\ (a+b):2=21=\ \textgreater \ a+b=42\\ =\ \textgreater \ 42+c=74=\ \textgreater \ c=32\\ (b+c):2=28=\ \textgreater \ b+32=56=\ \textgreater \ b=24\\ a+24+32=74=\ \textgreater \ a+56=74=\ \textgreater \ a=18.\\\\ Proba:18+32+24=74\\ 50+24=74\\ 74=74[/tex]