Tìm x, biết: (a) 5 /7 + 2 /7 : x = 1

(2,0 điểm) Tìm x, biết:

(a) \(\frac{5}{7} + \frac{2}{7}:x = 1\)

(b) \({\left( {\frac{4}{5}} \right)^{2x + 5}} = \frac{{256}}{{625}}\)

(c) \(2 - \left| x \right| = \frac{1}{2}\)

(d) \({\left( {x + \frac{1}{3}} \right)^2} = {\left( {\frac{2}{3}} \right)^6}\).