\(\frac{3}{4}=\frac{15}{20}\) => ô = 15
\(\frac{4}{5}=\frac{12}{15}\) => ô = 15
\(\frac{-4}{9}=\frac{-16}{36}\) => ô = - 4
\(\frac{7}{13}=\frac{21}{39}\) => ô = 13
a,\(\frac{3}{4}=\frac{15}{20}\)
b,\(\frac{4}{5}=\frac{12}{15}\)
c,\(\frac{-4}{9}=\frac{-16}{36}\)
d,\(\frac{7}{-13}=\frac{21}{-39}\)