Đáp án:
B1:
a) -9
Giải thích các bước giải:
\(\begin{array}{l}
B1:\\
a)\left( {\dfrac{8}{3} + \dfrac{4}{3}} \right):\dfrac{1}{4} - 25\\
= 4.4 - 25 = - 9\\
b)\dfrac{{{2^3}{{.5}^3} + {{2.5}^3} + {5^2}}}{{5.11}} = \dfrac{{{5^2}\left( {8.5 + 2.5 + 1} \right)}}{{5.11}}\\
= \dfrac{{5.51}}{{11}} = \dfrac{{255}}{{11}}\\
B2:\\
a)x + \dfrac{1}{2} = \dfrac{3}{4} - \dfrac{4}{5}\\
\to x + \dfrac{1}{2} = - \dfrac{1}{{20}}\\
\to x = - \dfrac{{11}}{{20}}\\
b)2x - 1 - 5x - 3 = - x + \dfrac{1}{3}\\
\to 2x = - \dfrac{{13}}{3}\\
\to x = - \dfrac{{13}}{6}
\end{array}\)
