2x=-8y<=>x/y=-8/2<=>x/-8=y/2
áp dụng t/c dãy t/s=nhau:
\(\frac{x}{-8}=\frac{y}{2}=\frac{x+y}{\left(-8\right)+2}=\frac{-54}{-6}=9\)
=>x/-8=9=>x=-72
y/2=9=>y=18
vậy...
ta có: 2x=-8y\(\Rightarrow\frac{x}{-8}=\frac{y}{2}=\frac{x+y}{-8+2}=\frac{-54}{-6}=\) 9
ta có:x=9* (-8)=-72
y=9*2=18