Răspuns
Explicație pas cu pas:
[tex]\{a,b,c\}~direct~proportional~\{7,8,10\}\Rightarrow \dfrac{a}{7}=\dfrac{b}{8}=\dfrac{c}{10}=k\Rightarrow a=7k,b=8k,\\ c=10k .\\a+b=45\\7k+8k=45\\15k=45\\\boxed{\bold{k=3}}\\a=7k\Rightarrow \boxed{a=21}\\b=8k\Rightarrow \boxed{b=24}\\c=10k\Rightarrow \boxed{c=30}[/tex]