Question

\(\dfrac{x}{2}\)=\(\dfrac{y}{3}\);\(\dfrac{y}{3}\)=\(\dfrac{z}{4}\)và x+y+z=-42

Answer 1

\(\dfrac{x}{2}=\dfrac{y}{3}=\dfrac{z}{4}=\dfrac{x+y+z}{2+3+4}=\dfrac{-42}{9}=-\dfrac{14}{3}\\ \Rightarrow\left\{{}\begin{matrix}x=-\dfrac{28}{3}\\x=-\dfrac{42}{3}\\x=-\dfrac{56}{3}\end{matrix}\right.\)

Answer 2

\(\dfrac{x}{2}=\dfrac{y}{3};\dfrac{y}{3}=\dfrac{z}{4}\Rightarrow\dfrac{x}{2}=\dfrac{y}{3}=\dfrac{z}{4}\)

Áp dụng t/c dtsbn ta có:

\(\dfrac{x}{2}=\dfrac{y}{3}=\dfrac{z}{4}=\dfrac{x+y+z}{2+3+4}=\dfrac{-42}{9}=-\dfrac{14}{3}\)

\(\dfrac{x}{2}=-\dfrac{14}{3}\Rightarrow x=-\dfrac{28}{3}\\ \dfrac{y}{3}=-\dfrac{14}{3}\Rightarrow y=-14\\ \dfrac{z}{4}=-\dfrac{14}{3}\Rightarrow z=-\dfrac{56}{3}\)

Answer 3

Áp dụng t/c dtsbn:

\(\dfrac{x}{2}=\dfrac{y}{3}=\dfrac{z}{4}=\dfrac{x+y+z}{2+3+4}=\dfrac{-42}{9}=\dfrac{-14}{3}\)

\(\Rightarrow\left\{{}\begin{matrix}x=\dfrac{-28}{3}\\y=-14\\z=\dfrac{-56}{3}\end{matrix}\right.\)