Tìm x, biết: (3,8:(2x) = frac{1}{4}:2 frac{2}{3} ) A. x = 20; B. (x = frac{{15}}{{304}} ); C. (x = 20 frac{4}{{15}} ) D. (x = frac{{ - 304}}{{15}} ).

Đáp án đúng là: C Ta có: 3,8 : (2x) = ( frac{1}{4}:2 frac{2}{3} ) ( frac{{3,8}}{{2x}} = frac{1}{4}: frac{8}{3} ) ( frac{{3,8}}{{2x}} = frac{1}{4}. frac{3}{8} ) ( frac{{3,8}}{{2x}} = frac{3}{{32}} ) 3,8 . 32 = 2x . 3 6x = 121,6 (x = frac{{121,6}}{6} ) (x = frac{{304}}{{15}} ). Vậy (x = frac{{304}}{{15}} ).