Tìm x , biết: a) x + 1/3 = -5/6

a) \(x + \frac{1}{3} = \frac{{ - 5}}{6}\)

 \[x = \frac{{ - 5}}{6} - \frac{1}{3}\]

 \[x = \frac{{ - 7}}{6}\].

Vậy \[x = \frac{{ - 7}}{6}.\]

 b) \(\left( {x - \frac{3}{5}} \right):\frac{{ - 1}}{3} = 0,4\)

 \[\left( {x - \frac{3}{5}} \right) = \frac{2}{5}.\frac{{ - 1}}{3}\]

 \[x = \frac{7}{{15}}\].

Vậy \[x = \frac{7}{{15}}.\]

 c) \({\left( {\frac{{ - 3}}{5}} \right)^7}:x = {\left( { - 0,6} \right)^3}.0,36\)

 \[{\left( {\frac{{ - 3}}{5}} \right)^7}:x = {\left( {\frac{{ - 3}}{5}} \right)^5}\]

 \[x = {\left( {\frac{{ - 3}}{5}} \right)^2} = \frac{9}{{25}}\].

Vậy \[x = \frac{9}{{25}}.\]