Tìm x biết 3/8 - (x - 4/15) = - 3/11 + 4/15 + 3/8.

Hướng dẫn giải:

Đáp án đúng là: A

\(\frac{3}{8} - \left( {x - \frac{4}{{15}}} \right) = \frac{{ - 3}}{{11}} + \frac{4}{{15}} + \frac{3}{8}\)

\(\frac{3}{8} - x + \frac{4}{{15}} = \frac{{ - 3}}{{11}} + \frac{4}{{15}} + \frac{3}{8}\)

\( - x = \frac{{ - 3}}{{11}} + \frac{4}{{15}} + \frac{3}{8} - \frac{3}{8} - \frac{4}{{15}}\)

\( - x = \frac{{ - 3}}{{11}} + \left( {\frac{4}{{15}} - \frac{4}{{15}}} \right) + \left( {\frac{3}{8} - \frac{3}{8}} \right)\)

\( - x = \frac{{ - 3}}{{11}}\)

\(x = \frac{3}{{11}}\)

Vậy \(x = \frac{3}{{11}}.\)