Question

Answer 1

\(\dfrac{x}{3}=\dfrac{y}{4}=\dfrac{z}{5}=\dfrac{2x}{6}=\dfrac{y}{4}=\dfrac{2x-y}{6-4}=\dfrac{20}{2}=10\)

\(\Rightarrow\left\{{}\begin{matrix}x=3.10=30\\y=4.10=40\\z=5.10=50\end{matrix}\right.\)

b.

\(\dfrac{a}{b}=\dfrac{b}{c}=\dfrac{c}{a}=\dfrac{a+b+c}{b+c+a}=1\)

\(\Rightarrow\left\{{}\begin{matrix}\dfrac{a}{b}=1\\\dfrac{b}{c}=1\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}a=b\\b=c\end{matrix}\right.\) \(\Rightarrow a=b=c\)