a,\(\frac{x-1}{5}\)=\(\frac{y-2}{2}\)=\(\frac{z-2}{3}\).và x+y2-z=6
b,\(\frac{2x}{3}\)=\(\frac{3y}{4}\)=\(\frac{4z}{5}\)và x+y+z=49
c,\(\frac{6}{11}x\)=\(\frac{9}{2}y\)=\(\frac{18}{5}z\)và x+y+z=28
d,\(\frac{x}{y}\)=\(\frac{2}{3}\):\(\frac{x}{z}\)=\(\frac{1}{2}\)và x3+y3+z3=99
Ta có : \(\frac{x-1}{5}=\frac{y-2}{2}=\frac{z-2}{3}=\frac{2y-4}{4}=\frac{x-1+2y-4-\left(z-2\right)}{5+4-3}=\frac{x-1+2y-4-z+2}{6}\)
\(=\frac{x+2y-z-3}{6}=\frac{3}{6}=\frac{1}{2}\)
Nên : \(\frac{x-1}{5}=\frac{1}{2}\Rightarrow x-1=\frac{5}{2}\Rightarrow x=\frac{7}{2}\)
\(\frac{y-2}{2}=\frac{1}{2}\Rightarrow y-2=1\Rightarrow y=3\)
\(\frac{z-2}{3}=\frac{1}{2}\Rightarrow z-2=\frac{3}{2}\Rightarrow z=\frac{7}{2}\)
Vậy ,,,,,,,,,,,,,,,,,,