a,x-\(\frac23\) =\(-\frac{5}{12}\)

x=\(\frac{-5}{12}\) +\(\frac23\)

x=\(-\frac{5}{12}\) +\(\frac{8}{12}\)

x=\(\frac{3}{12}\)

x=\(\frac14\)

Vậy x=\(\frac14\)

b,\(\frac85\) :x = \(-\frac23\)

x = \(\frac85\) : \(-\frac23\)

x=\(\frac85\) •\(\frac{-3}{2}\)

x=\(\frac{-12}{5}\)

Vậy x=\(\frac{-12}{5}\)

c,1-\(\frac37\) •x=\(\frac{-2}{7}\)

\(\frac37\) •x=1-\(\frac{-2}{7}\)

\(\frac37\) •x = 1+ \(\frac27\)

\(\frac37\) • x = \(\frac77\) + \(\frac27\)

\(\frac37\) •x = \(\frac99\)

\(\frac37\) •x = 1

x= 1 :\(\frac37\)

x = 1 • \(\frac37\)

x= \(\frac37\)

Vậy x= \(\frac37\)

a,\(\frac{-2}{7}\) +\(\frac{2}{\overline{7}}\) :\(\frac35\)

=\(\frac{-2}{7}\) +\(\frac27\) . \(\frac53\)

=\(\frac{-2}{7}\) +\(\frac{15}{21}\)

=\(\frac{-6}{21}\) +\(\frac{15}{21}\)

= \(\frac{9}{21}\)

= \(\frac37\)

b,\(-\frac{8}{19}\) + \(-\frac{4}{21}\) - \(\frac{17}{21}\) + \(\frac{27}{19}\)

= \(-\frac{8}{19}\) + \(-\frac{4}{21}\) + \(-\frac{17}{21}\) + \(\frac{27}{19}\)

=(\(-\frac{8}{19}\) + \(\frac{27}{19}\) )+ ( \(-\frac{4}{21}\) + \(-\frac{17}{21}\) )

=1+(-1)

= 0

c,\(\frac65\) •\(\frac{3}{13}\) - \(\frac65\) • \(\frac{16}{13}\)

= \(\frac65\) •(\(\frac{3}{13}\) - \(\frac{16}{13}\) )

= \(\frac65\) • (-1)

= \(-\frac{6}{13}\)