Răspuns :
a+b+c=18×3=54
b=2×a
c=3×b => c=3×2×a c=6×a
a+2×a+6×a=9×a
9×a=54
a=54:9=6
Cu plăcere
[tex] \frac{a+b+c}{3} =18 \\ a+b+c=18*3 \\ a+b+c=54 \\ b=2a =\ \textgreater \ a= \frac{b}{2} \\ c=3b \\ b/2+b+3b=54 \\ b+2b+6b=108 \\ 9b=208=\ \textgreater \ b=108:9=\ \textgreater \ b=12 \\ a=12:2=6 \\ c=3*12=36[/tex]