Đáp án + Giải thích các bước giải:
a)
$11\dfrac{3}{13} - \bigg(2\dfrac{4}{7} + 5\dfrac{3}{13}\bigg)\\$
$=11\dfrac{3}{13} - 2\dfrac{4}{7} - 5\dfrac{3}{13}\\$
$=\bigg(11\dfrac{3}{13} - 5\dfrac{3}{13}\bigg) - 2\dfrac{4}{7}\\$
$=6 - 2\dfrac{4}{7}\\$
$=6 - \dfrac{18}{7}\\$
$=\dfrac{24}{7}\\$
b)
$\dfrac{4}{7} + \dfrac{5}{6} : 5 - 0,375 . (-2)^2$
$=\dfrac{4}{7} + \dfrac{5}{6} : 5 - \dfrac{3}{8} . 4\\$
$=\dfrac{4}{7} + \dfrac{1}{6} - \dfrac{3}{2}\\$
$=\dfrac{24}{42} + \dfrac{7}{42} - \dfrac{63}{42}\\$
$=\dfrac{-16}{21}\\$
c)
$\dfrac{1}{4} + \dfrac{3}{4} . \bigg(\dfrac{-1}{2} + \dfrac{2}{3}\bigg)\\$
$=\dfrac{1}{4} + \dfrac{3}{4} . \bigg(\dfrac{-3}{6} + \dfrac{4}{6}\bigg)\\$
$=\dfrac{1}{4} + \dfrac{3}{4} . \dfrac{1}{6}\\$
$=\dfrac{1}{4} + \dfrac{1}{8}\\$
$=\dfrac{2}{8} + \dfrac{1}{8}\\$
$=\dfrac{3}{8}$
