Question

Tìm x, y, z biết:
c, \(5x=8y=20z;x-y-z=3\)

Answer 1

5x = 8y = 20z = \(\dfrac{x}{8}=\dfrac{y}{5}=\dfrac{z}{8}\)

Dựa vào tính chất dãy tỉ số bằng nhau, ta được:

\(\dfrac{x-y-z}{8-5-8}=\dfrac{3}{-5}\)

=> 5x = 8y = 20z = \(\dfrac{3}{-5}\)

=> \(\left\{{}\begin{matrix}x=-\dfrac{3}{25}\\y=-\dfrac{3}{40}\\z=-\dfrac{3}{100}\end{matrix}\right.\)

Answer 2

8y = 20z = \(\dfrac{y}{20}=\dfrac{z}{8}\)

Mà 5x = 8y = \(\dfrac{x}{8}=\dfrac{y}{5}\)

Nên mik cho \(\dfrac{x}{8}=\dfrac{y}{5}=\dfrac{z}{8}\) luôn.