[tex]\{a,b\} ip\{3,7\}\Rightarrow \frac{a}{\frac{1}{3}}=\frac{b}{\frac{1}{7}}=k\Rightarrow a=\frac{k}{3},b=\frac{k}{7}\\
a\cdot b+a^2+b^2=316\\
\frac{k}{3}\cdot \frac{k}{7}+\frac{k^2}{49}+\frac{k^2}{9}=316\\
\frac{k^2}{21}+\frac{k^2}{49}+\frac{k^2}{9}=316|\cdot 441\\
21k^2+9k^2+49k^2=139356\\
79k^2=139356\\
k^2=1764 \Rightarrow k=42\\
a=\frac{42}{3}=14\\
Raspuns\ final:D.[/tex]
