Giúp em với . Em cảm ơn nhiều
9. a) \(\dfrac{4}{3}+\dfrac{2}{3}:x=-\dfrac{2}{5}\)
\(\Rightarrow\dfrac{2}{3}:x=-\dfrac{26}{15}\)\(\Rightarrow x=\dfrac{2}{3}:\left(-\dfrac{26}{15}\right)=-\dfrac{5}{13}\)
b) \(\dfrac{7}{3}-1\dfrac{3}{5}.x=-1\dfrac{2}{3}\)
\(\Rightarrow\dfrac{8}{5}x=\dfrac{7}{3}-\left(-\dfrac{5}{3}\right)=\dfrac{7+5}{3}\)
\(\Rightarrow\dfrac{8}{5}x=4\Leftrightarrow x=\dfrac{5}{2}\)
c) \(\left(-2\dfrac{1}{4}:x+1,5\right)\left(\dfrac{-5}{3}.x-\dfrac{5}{12}\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}-2\dfrac{1}{4}:x=-1.5\\\dfrac{-5}{3}.x=\dfrac{5}{12}\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}x=\dfrac{3}{2}\\x=-\dfrac{1}{4}\end{matrix}\right.\)
d) \(-\dfrac{3}{5}.x-\left(x+2,5\right)=-\dfrac{13}{15}\)
\(\Rightarrow-\dfrac{8}{5}.x=-\dfrac{13}{15}+2,5\)
\(\Rightarrow-\dfrac{8}{5}.x=\dfrac{49}{30}\)
\(\Rightarrow x=\dfrac{49}{30}:\left(\dfrac{-8}{5}\right)=-\dfrac{49}{48}\)
10.
a) \(\left(-3+\dfrac{3}{x}-\dfrac{1}{3}\right):\left(1+\dfrac{2}{5}+\dfrac{2}{3}\right)=-\dfrac{5}{4}\)
\(\Rightarrow\left(\dfrac{3}{x}-\dfrac{10}{3}\right):\dfrac{31}{15}=-\dfrac{5}{4}\)
\(\Rightarrow\dfrac{3}{x}-\dfrac{10}{3}=-\dfrac{5}{4}.\dfrac{31}{15}=-\dfrac{31}{12}\)
\(\Rightarrow\dfrac{3}{x}=-\dfrac{31}{12}+\dfrac{10}{3}=\dfrac{3}{4}\)
\(\Leftrightarrow x=4\)
b) \(\left(\dfrac{2}{5}-x\right):1\dfrac{1}{3}+\dfrac{1}{2}=-4\)
\(\Rightarrow\left(\dfrac{2}{5}-x\right):\dfrac{4}{3}=-4-\dfrac{1}{2}=-\dfrac{9}{2}\)
\(\Rightarrow\dfrac{2}{5}-x=-\dfrac{9}{2}.\dfrac{4}{3}=-6\)
\(\Rightarrow x=\dfrac{2}{5}-\left(-6\right)=\dfrac{32}{5}\)
c) \(-\dfrac{3x}{4}.\left(\dfrac{1}{x}+\dfrac{2}{7}\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}-\dfrac{3x}{4}=0\\\dfrac{1}{x}+\dfrac{2}{7}=0\end{matrix}\right.\) \(\Leftrightarrow\left[{}\begin{matrix}x=0\\\dfrac{1}{x}=-\dfrac{2}{7}\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=-\dfrac{7}{2}\end{matrix}\right.\)
d) \(2,5x+\dfrac{-4}{7}=\dfrac{1}{2}x\)
\(\Rightarrow2,5x-\dfrac{1}{2}x=\dfrac{4}{7}\)
\(\Rightarrow2x=\dfrac{4}{7}\Leftrightarrow x=\dfrac{2}{7}\)
