Tìm x biết \(\frac{3}{8} - \left( {x - \frac{4}} \right) = \frac{{ - 3}} + \frac{4} + \frac{3}{8}\).

Hướng dẫn giải:

Đáp án đúng là: A

\(\frac{3}{8} - \left( {x - \frac{4}} \right) = \frac{{ - 3}} + \frac{4} + \frac{3}{8}\)

\(\frac{3}{8} - x + \frac{4} = \frac{{ - 3}} + \frac{4} + \frac{3}{8}\)

\( - x = \frac{{ - 3}} + \frac{4} + \frac{3}{8} - \frac{3}{8} - \frac{4}\)

\( - x = \frac{{ - 3}} + \left( {\frac{4} - \frac{4}} \right) + \left( {\frac{3}{8} - \frac{3}{8}} \right)\)

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

\(x = \frac{3}\)

Vậy \(x = \frac{3}.\)