Đáp án:
B2:
b) \(x = - \dfrac{{23}}{{32}}\)
Giải thích các bước giải:
\(\begin{array}{l}
B1:\\
a)\dfrac{{3.3 - 5.2 + 11}}{{12}} = \dfrac{{9 - 10 + 11}}{{12}}\\
= \dfrac{{ - 1 + 11}}{{12}} = \dfrac{{10}}{{12}} = \dfrac{5}{6}\\
b)\dfrac{{ - 16}}{{11}}:\dfrac{{12}}{{5.11}}\\
= \dfrac{{ - 16}}{{11}}.\dfrac{{5.11}}{{12}} = - \dfrac{{20}}{3}\\
c)\dfrac{{16}}{5}.\left( { - \dfrac{{15}}{{64}}} \right) - \dfrac{{22}}{{15}}:\dfrac{{11}}{3}\\
= - \dfrac{3}{4} - \dfrac{{22}}{{15}}.\dfrac{3}{{11}}\\
= - \dfrac{3}{4} - \dfrac{2}{5} = - \dfrac{{23}}{{20}}\\
B2:\\
a)x - \dfrac{2}{5} = \dfrac{9}{{15}}\\
\to x = \dfrac{9}{{15}} + \dfrac{2}{5}\\
\to x = 1\\
b)\left( {\dfrac{7}{2} + 2x} \right).\dfrac{8}{3} = \dfrac{{11}}{2}\\
\to \dfrac{7}{2} + 2x = \dfrac{{33}}{{16}}\\
\to 2x = \dfrac{{33}}{{16}} - \dfrac{7}{2}\\
\to 2x = - \dfrac{{23}}{{16}}\\
\to x = - \dfrac{{23}}{{32}}
\end{array}\)
