a) 2\(\frac{2}{3}:x=\)1\(\frac{7}{9}:\)2\(\frac{2}{3}\)
\(\frac{8}{3}:x=\frac{16}{9}:\frac{8}{3}\)
\(\frac{8}{3}:x=\frac{16}{9}.\frac{3}{8}\)
\(\frac{8}{3}:x=\frac{2}{3}\)
x =\(\frac{8}{3}:\frac{2}{3}\)
\(x=\frac{8}{3}.\frac{3}{2}\)
\(x=4\)
Vậy x=4