Question

Tìm các số x, y , z biết rằng : x : 2 = y : 3 = z : 2 và x - 2y + 3z = 4

Answer 1

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

\(\dfrac{x}{2}-\dfrac{2y}{6}+\dfrac{3z}{6}=\dfrac{x-2y+3z}{2-6+6}=\dfrac{4}{2}=2\)

Vậy

\(\dfrac{x}{2}=2\Rightarrow x=4\)

\(\dfrac{y}{3}=2\Rightarrow y=6\)

\(\dfrac{z}{2}=2\Rightarrow z=4\)

Answer 2

\(\dfrac{x}{2}=\dfrac{y}{3}=\dfrac{z}{2}\Leftrightarrow\dfrac{x}{2}=\dfrac{2y}{6}=\dfrac{3z}{6}\)

Áp dụng tính chất dãy tỉ số bằng nhau ta có:

\(\dfrac{x}{2}=\dfrac{2y}{6}=\dfrac{3z}{6}=\dfrac{x-2y+3z}{2-6+6}=\dfrac{4}{2}=2\)

\(\Rightarrow\left\{{}\begin{matrix}x=2.2=4\\y=2.3=6\\z=2.2=4\end{matrix}\right.\)

Answer 3

Bao giờ bn c*ần