Đáp án:
\(\begin{array}{l}
f)\dfrac{{10584}}{{1045}}\\
g)\dfrac{{69}}{8}\\
h)\dfrac{1}{{71}}\\
j)\dfrac{{69}}{{10}}\\
k)\dfrac{5}{3}
\end{array}\)
Giải thích các bước giải:
\(\begin{array}{l}
f)\left( {\dfrac{{240}}{{11}}:\dfrac{{38}}{{49}} - \dfrac{{24}}{{11}}:\dfrac{{38}}{{49}}} \right):\dfrac{5}{2}\\
= \left( {\dfrac{{240}}{{11}} - \dfrac{{24}}{{11}}} \right):\dfrac{{38}}{{49}}.\dfrac{2}{5}\\
= \dfrac{{216}}{{11}}.\dfrac{{49}}{{38}}.\dfrac{2}{5}\\
= \dfrac{{5292}}{{209}}.\dfrac{2}{5} = \dfrac{{10584}}{{1045}}\\
g)8 + \dfrac{5}{{11}} + 3 + \dfrac{5}{8} - 3 - \dfrac{5}{{11}}\\
= 8 + \dfrac{5}{8} = \dfrac{{69}}{8}\\
h) - \dfrac{1}{2} + \dfrac{3}{5} - \dfrac{1}{9} + \dfrac{1}{{71}} + \dfrac{2}{7} + \dfrac{4}{{35}} - \dfrac{7}{{18}}\\
= \dfrac{{ - 9 - 2 - 7}}{{18}} + \dfrac{{21 + 10 + 4}}{{35}} + \dfrac{1}{{71}}\\
= - 1 + 1 + \dfrac{1}{{71}} = \dfrac{1}{{71}}\\
j)7 - \dfrac{1}{4} + \dfrac{2}{3} - 5 + \dfrac{1}{3} + \dfrac{7}{5} + 6 - \dfrac{7}{4} - \dfrac{3}{2}\\
= 8 + \left( { - \dfrac{1}{4} - \dfrac{7}{4}} \right) + \left( {\dfrac{2}{3} + \dfrac{1}{3}} \right) + \dfrac{7}{5} - \dfrac{3}{2}\\
= 8 - 2 + 1 - \dfrac{1}{{10}} = \dfrac{{69}}{{10}}\\
k)\dfrac{{\dfrac{5}{8} + \dfrac{5}{7} - \dfrac{5}{4} - \dfrac{5}{{11}}}}{{\dfrac{3}{8} + \dfrac{3}{7} - \dfrac{3}{{11}} - \dfrac{3}{4}}} = \left[ {5.\left( {\dfrac{1}{8} + \dfrac{1}{7} - \dfrac{1}{{11}} - \dfrac{1}{4}} \right)} \right]:\left[ {3.\left( {\dfrac{1}{8} + \dfrac{1}{7} - \dfrac{1}{{11}} - \dfrac{1}{4}} \right)} \right]\\
= \dfrac{5}{3}
\end{array}\)
