S.56 T.171

a)
6\cdot\frac{4}{3}=8
8\cdot\frac{4}{3}=10\frac{2}{3}
b)
\frac{48}{x}=\left(\frac{4}{3}\right)^2
\frac{48}{x}=\frac{10}{9}
16x=432
x=27
\frac{48}{27}=\frac{16}{9}=16:9