Đáp án:
$A = -\frac{11}{5}$
$B = \frac{12}{17}$
$C = -1$
$D = 0$
$E = \frac{14}{27}$
$F = - 6$
Giải thích các bước giải:
$a. A = ( -2\frac{1}{5} + \frac{2}{7} - \frac{12}{13} ) - ( \frac{-5}{7} + \frac{1}{13} )$
$A = - 2\frac{1}{5} + \frac{2}{7} - \frac{12}{13} + \frac{5}{7} - \frac{1}{13}$
$A = - 2\frac{1}{5} + ( \frac{2}{7} + \frac{5}{7} ) + ( - \frac{12}{13} - \frac{1}{13} )$
$A = - 2\frac{1}{5} + 1 - 1$
$A = - 2\frac{1}{5}$
$A = -\frac{11}{5}$
$b. B = \frac{12}{17}.\frac{5}{7} - \frac{-12}{17}.\frac{1}{7} + \frac{1}{17.7}.12$
$B = \frac{12}{17}.\frac{5}{7} + \frac{12}{17}.\frac{1}{7} + \frac{12}{17}.\frac{1}{7}$
$B = \frac{12}{17}.( \frac{5}{7} + \frac{1}{7} + \frac{1}{7} )$
$B = \frac{12}{17}.\frac{7}{7}$
$B = \frac{12}{17}$
$c. C = ( \frac{1}{3} - 2\frac{1}{6} )^{2} : ( - 3\frac{13}{16} )$
$C = ( \frac{2}{6} - \frac{13}{6} )^{2} : (-\frac{121}{36})$
$C = (\frac{11}{6})^{2}.\frac{-36}{121}$
$C = \frac{121}{36}.\frac{-36}{121}$
$C = -1$
$d. D = ( \frac{5}{-6} + \frac{2}{5} ) : \frac{3}{8} + ( \frac{4}{5} - \frac{11}{30} ) : \frac{3}{8}$
$D = ( \frac{-5}{6} + \frac{2}{5} ).\frac{8}{3} + ( \frac{4}{5} - \frac{11}{30} ).\frac{8}{3}$
$D = \frac{8}{3}.( \frac{-5}{6} + \frac{2}{5} + \frac{4}{5} - \frac{11}{30} )$
$D = \frac{8}{3}.( \frac{-25}{30} + \frac{6}{5} - \frac{11}{30} )$
$D = \frac{8}{3}.( - \frac{25}{30} - \frac{11}{30} + \frac{6}{5} )$
$D = \frac{8}{3}.( - \frac{36}{30} + \frac{6}{5} )$
$D = \frac{8}{3}.( - \frac{6}{5} + \frac{6}{5} )$
$D = 0$
$e. E = 1 - \frac{13}{27}.\frac{60}{41} + \frac{13}{27}.\frac{19}{41}$
$E = 1 - \frac{13}{27}.( \frac{60}{41} - \frac{19}{41} )$
$E = 1 - \frac{13}{27}.\frac{41}{41}$
$E = 1 - \frac{13}{27}$
$E = \frac{14}{17}$
$f. F = ( 9\frac{3}{4} : 5,2 + 3,4.2\frac{7}{34} ) : (-1\frac{9}{16})$
$F = ( \frac{39}{4} : \frac{52}{10} + \frac{34}{10}.\frac{75}{10} ) : (-\frac{25}{16})$
$F = ( \frac{13.3}{2.2} : \frac{13.4}{2.5} + \frac{75}{10} ).\frac{-16}{25}$
$F = ( \frac{13.3}{2.2}.\frac{2.5}{13.4} + \frac{15.5}{2.5} ).\frac{-16}{25}$
$F = ( \frac{15}{8} + \frac{15}{2} ).\frac{-16}{25}$
$F = ( \frac{15}{8} + \frac{15.4}{8} ).\frac{-16}{25}$
$F = \frac{75}{8}.\frac{-16}{25}$
$F = \frac{3.25}{8}.\frac{-2.8}{25}$
$F = - 6$
