d) \(\dfrac{1}{2}x+2\dfrac{1}{2}=3\dfrac{1}{2}x-\dfrac{3}{4}\)
\(\Rightarrow\dfrac{1}{2}x+\dfrac{5}{2}=\dfrac{7}{2}x-\dfrac{3}{4}\)
\(\Rightarrow\dfrac{7}{2}x-\dfrac{1}{2}x=\dfrac{5}{2}+\dfrac{3}{4}\)
\(\Rightarrow3x=\dfrac{13}{4}\)
\(\Rightarrow x=\dfrac{13}{4}:3\)
\(\Rightarrow x=\dfrac{13}{12}\)
e) \(\dfrac{2}{3}x-\dfrac{2}{5}=\dfrac{1}{2}x-\dfrac{1}{3}\)
\(\Rightarrow\dfrac{2}{3}x-\dfrac{1}{2}x=-\dfrac{1}{3}+\dfrac{2}{5}\)
\(\Rightarrow\dfrac{1}{6}x=\dfrac{1}{15}\)
\(\Rightarrow x=\dfrac{1}{15}:\dfrac{1}{6}\)
\(\Rightarrow x=\dfrac{6}{15}\)
\(\Rightarrow x=\dfrac{2}{5}\)
f) \(\left(\dfrac{1}{3}x+\dfrac{2}{5}\right)\left(x+1\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}\dfrac{1}{3}x+\dfrac{2}{5}=0\\x+1=0\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}\dfrac{1}{3}x=-\dfrac{2}{5}\\x=-1\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=-\dfrac{2}{5}:\dfrac{1}{3}\\x=-1\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=-\dfrac{6}{5}\\x=-1\end{matrix}\right.\)
d: =>1/2x-7/2x=-3/4-5/2
=>-3x=-3/4-10/4=-13/4
=>3x=13/4
=>x=13/4:3=13/12
e: =>2/3x-1/2x=-1/3+2/5
=>1/6x=-5/15+6/15=1/15
=>x=1/15*6=6/15=2/5
f: (1/3x+2/5)(x+1)=0
=>1/3x+2/5=0 hoặc x+1=0
=>x=-1 hoặc x=-2/5:1/3=-6/5
