Question

x/2=y/4=z/-5va 2x-y+3z=1200

Answer 1

Theo bài ra ta có:

\(\frac{x}{2}=\frac{y}{4}=\frac{z}{-5}\)  

 \(\Rightarrow\frac{2x}{4}=\frac{y}{4}=\frac{3z}{-15}\) và \(2x-y+3z=1200\)

AD: T/c dãy tỉ số bằng nhau ta có:

\(\frac{x}{2}=\frac{y}{4}=\frac{z}{-5}=\frac{2x}{4}=\frac{3z}{-15}=\frac{2x-y+3z}{4-4+\left(-15\right)}=\frac{1200}{-15}=-80\)

\(\Rightarrow\)\(\hept{\begin{cases}x=80.2=160\\y=80.4=320\\z=80.\left(-5\right)=-400\end{cases}}\)

Vậy x = 160, y = 320, z = -400