Tìm \(x,\) biết: a) \[\frac{2}{5} + \frac{3}{5}x = 0.\]                                 b) \( - 0,6 + x = 0,5.\)      c) \(\frac{1}{3}:x + \left( { - \frac{3}{4} + \frac{2}{3}} \right):x =

a) \[\frac{2}{5} + \frac{3}{5}x = 0\]

 \[\frac{3}{5}x =  - \frac{2}{5}\]

 \[x = \frac{{ - 2}}{5}:\frac{3}{5}\]

 \[x = \frac{{ - 2}}{5} \cdot \frac{5}{3}\]

 \[x = \frac{{ - 2}}{3}.\]

Vậy \[x = \frac{{ - 2}}{3}.\]

b) \( - 0,6 + x = 0,5\)

\(x = 0,5 - \left( { - 0,6} \right)\)

\(x = 0,5 + 0,6\)

\(x = 1,1.\)

Vậy \(x = 1,1.\)

c) \(\frac{1}{3}:x + \left( { - \frac{3}{4} + \frac{2}{3}} \right):x = \frac{5}{8}\)

 \(\frac{1}{3} \cdot \frac{1}{x} - \frac{1}{{12}} \cdot \frac{1}{x} = \frac{5}{8}\)

 \(\left( {\frac{1}{3} - \frac{1}{{12}}} \right) \cdot \frac{1}{x} = \frac{5}{8}\)

 \(\frac{1}{4} \cdot \frac{1}{x} = \frac{5}{8}\)

 \(\frac{1}{x} = \frac{5}{2}\)

 \(x \cdot 5 = 1 \cdot 2\)

 \(5x = 2\)

     \(x = \frac{2}{5}\)

Vậy \(x = \frac{2}{5}.\)