Răspuns :
a,(a+1),(a+2) - numerele consecutive.
a=?
[tex] \frac{a+a+1+a+2}{3} [/tex]=19 =>[tex] \frac{3a+3}{3} = \frac{19}{1} [/tex] =>3a+3=19*3 => 3a+3=57=>3a=54=>a=18
Chiar daca nu ti se cere: a+1=18+1=19
a+2=18+2=20
Numerele sunt: {18,19,20}
a=?
[tex] \frac{a+a+1+a+2}{3} [/tex]=19 =>[tex] \frac{3a+3}{3} = \frac{19}{1} [/tex] =>3a+3=19*3 => 3a+3=57=>3a=54=>a=18
Chiar daca nu ti se cere: a+1=18+1=19
a+2=18+2=20
Numerele sunt: {18,19,20}
asta este rezolvarea. daca ai neclaritati, ma intrebi. sper ca se intelege