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