Question

x/2=y/3=z/5 và x.y.z=-30

Answer 1

đặt \(\dfrac{x}{2}=\dfrac{y}{3}=\dfrac{z}{5}=k\Rightarrow x=2k,y=3k,z=5k\)

Ta có: \(xyz=-30\Rightarrow2k.3k.5k=-30\\ \Rightarrow30.k^3=-30\\ \Rightarrow k^3=-1\\ \Rightarrow k=-1\\ \Rightarrow\left\{{}\begin{matrix}x=-2\\y=-3\\z=-5\end{matrix}\right.\)

Answer 2

x=-2

y=-3

z=-5

Answer 3

\(\dfrac{x}{2}\)=\(\dfrac{y}{3}\)=\(\dfrac{z}{5}\)=\(\dfrac{x+y+z}{2+3+5}\)=\(\dfrac{-30}{10}\)=-3

\(\Rightarrow\) x=(-3).2 = -6
    y=(-3).3 = -9
    z=(-3).5 = -15