Đáp án: $x=\dfrac{120}{31}, y=-\dfrac{200}{31}, z=\dfrac{160}{31}$
Giải thích các bước giải:
Ta có:
$\dfrac{x}{3}=\dfrac{y}{-5}=\dfrac{z}{4}=\dfrac{2x}{6}=\dfrac{-5y}{25}=\dfrac{2x-5y}{6+25}=\dfrac{40}{31}$
$\to x=\dfrac{120}{31}, y=-\dfrac{200}{31}, z=\dfrac{160}{31}$