a+b+c=21 0,2a/ (1/3) =0,25b/(35/48)= 0,3c/1 ⇒0,6a=12b/35 =c ⇒ b=7/4·a = 1,75a c=0,6a ⇒ a+1,75a+0,6a = 21 ⇒ 3,35a = 21 a=21/3,35 = 2100/335 = 420/67 a=420/67 b=7/4×420/67 = 735/67 b=735/67 c=0,6 ·420/67 = 252/67 c=252/67 (verifica daca enuntul sau calculele sunt corecte)