Đáp án:

Bạn tham khảo nhé.

Giải thích các bước giải:

$d)\,\dfrac67\!:\!\left(\dfrac3{26}-\dfrac3{13}\right)+\dfrac67\left(\dfrac1{10}-\dfrac85\right)\\=\dfrac67\!:\!\dfrac{-3}{26}+\dfrac67\!\cdot\!\dfrac{-3}2\\=\dfrac67\!\cdot\!\dfrac{-26}3+\dfrac67\!\cdot\!\dfrac{-3}2\\=\dfrac67\left(\dfrac{-26}3+\dfrac{-3}2\right)\\=\dfrac67\!\cdot\!\dfrac{-61}6\\=\dfrac{-61}7\\e)\,\left|\dfrac{-3}2+1,2\right|+1\dfrac23:6\\=\left|\dfrac{-3}2+\dfrac65\right|+\dfrac53:6\\=\left|\dfrac{-3}{10}\right|+\dfrac5{18}\\=\dfrac3{10}+\dfrac5{18}\\=\dfrac{26}{45}\\f)\,0,5\sqrt{100}-\sqrt{\dfrac14}+6,5:\left(2\dfrac14-1\dfrac16\right)\\=0,5.10-\dfrac12+\dfrac{13}2:\left(\dfrac94-\dfrac76\right)\\=5-\dfrac12+\dfrac{13}2:\dfrac{13}{12}\\=\dfrac92+6\\=\dfrac{21}2$

#andy

\[\begin{array}{l}
d)\dfrac{6}{7}:\left( {\dfrac{3}{{26}} - \dfrac{3}{{13}}} \right) + \dfrac{6}{7}.\left( {\dfrac{1}{{10}} - \dfrac{8}{5}} \right)\\
 = \dfrac{6}{7}:\left( { - \dfrac{3}{{26}}} \right) + \dfrac{6}{7}.\left( { - \dfrac{3}{2}} \right)\\
 = \dfrac{6}{7}.\left( { - \dfrac{{26}}{3}} \right) + \dfrac{6}{7}.\left( { - \dfrac{3}{2}} \right)\\
 = \dfrac{6}{7}.\left( { - \dfrac{{26}}{3} - \dfrac{3}{2}} \right)\\
 = \dfrac{6}{7}.\left( { - \dfrac{{61}}{6}} \right)\\
 =  - \dfrac{{61}}{7}\\
2)\left| { - \dfrac{3}{2} + 1,2} \right| + 1\dfrac{2}{3}:6\\
 = \left| { - \dfrac{3}{2} + \dfrac{6}{5}} \right| + \dfrac{5}{3}.\dfrac{1}{6}\\
 = \dfrac{3}{{10}} + \dfrac{5}{{18}}\\
 = \dfrac{{26}}{{45}}\\
f)0,5\sqrt {100}  - \sqrt {\dfrac{1}{4}}  + 6,5:\left( {2\dfrac{1}{4} - 1\dfrac{1}{6}} \right)\\
 = 5 - \dfrac{1}{2} + \dfrac{{13}}{2}:\left( {\dfrac{9}{4} - \dfrac{7}{6}} \right)\\
 = \dfrac{9}{2} + \dfrac{{13}}{2}:\dfrac{{13}}{{12}}\\
 = \dfrac{9}{2} + \dfrac{{13}}{2}.\dfrac{{12}}{{13}}\\
 = \dfrac{9}{2} + 6\\
 = \dfrac{{21}}{2}
\end{array}\]