1000 số 

=5 k mink nha

a ) \(\frac{4}{7}\) = \(\frac{4\cdot5}{7\cdot5}\) = \(\frac{20}{35}\)

\(\frac{16}{35}\) giữ ngyên

\(\frac{16}{35}\) < \(\frac{20}{35}\) . Vậy \(\frac{4}{7}\) > \(\frac{16}{35}\)

b ) \(\frac{13}{15}\) = \(\frac{13\cdot12}{15\cdot12}\) = \(\frac{156}{180}\)

\(\frac{11}{12}\) = \(\frac{11\cdot15}{12\cdot15}\) = \(\frac{165}{180}\)

\(\frac{156}{180}\) < \(\frac{165}{180}\) nên \(\frac{13}{15}\) < \(\frac{11}{12}\)