Đáp án:
l) \(\left[ \begin{array}{l}
x = 10\\
x = - 8
\end{array} \right.\)
Giải thích các bước giải:
\(\begin{array}{l}
a)x = - \dfrac{3}{{15}}.10\\
\to x = - 2\\
b)x = \dfrac{4}{6}.\left( { - 3} \right)\\
\to x = - 2\\
c)x = 5:\left( { - \dfrac{4}{{20}}} \right)\\
\to x = - 25\\
d)x = - \dfrac{2}{3}.9\\
\to x = - 6\\
e)x = - 6:\dfrac{3}{8}\\
\to x = - 16\\
f)\left\{ \begin{array}{l}
x = 5:\dfrac{2}{{10}}\\
y = \dfrac{2}{{10}}.\left( { - 15} \right)
\end{array} \right.\\
\to \left\{ \begin{array}{l}
x = 25\\
y = - 3
\end{array} \right.\\
g)\left\{ \begin{array}{l}
x = - 6.\dfrac{3}{9}\\
y = 4:\dfrac{3}{9}
\end{array} \right.\\
\to \left\{ \begin{array}{l}
x = - 2\\
y = 12
\end{array} \right.\\
h)x + 2 = \dfrac{3}{{21}}.14\\
\to x + 2 = 2\\
\to x = 0\\
i)x - 5 = \dfrac{{12}}{{15}}.10\\
\to x - 5 = 8\\
\to x = 13\\
j)x + 2 = \dfrac{1}{2}.7\\
\to x + 2 = \dfrac{7}{2}\\
\to x = \dfrac{3}{2}\\
k)x - 1 = 3:\dfrac{1}{7}\\
\to x - 1 = 21\\
\to x = 22\\
l)\left| {x - 1} \right| = \dfrac{3}{4}.12\\
\to \left| {x - 1} \right| = 9\\
\to \left[ \begin{array}{l}
x - 1 = 9\\
x - 1 = - 9
\end{array} \right.\\
\to \left[ \begin{array}{l}
x = 10\\
x = - 8
\end{array} \right.
\end{array}\)
