a) \(\dfrac{1}{2}x+\dfrac{3}{5}x=\dfrac{-22}{25}\)
\(\Rightarrow x\cdot\left(\dfrac{1}{2}+\dfrac{3}{5}\right)=\dfrac{-22}{25}\)
\(\Rightarrow x\cdot\dfrac{11}{10}=\dfrac{-22}{25}\)
\(\Rightarrow x=\dfrac{-22}{25}:\dfrac{11}{10}\)
\(\Rightarrow x=\dfrac{-4}{5}\)
b) \(\dfrac{6}{7}x-\dfrac{1}{2}x=\dfrac{15}{28}\)
\(\Rightarrow x\cdot\left(\dfrac{6}{7}-\dfrac{1}{2}\right)=\dfrac{15}{28}\)
\(\Rightarrow x\cdot\dfrac{5}{14}=\dfrac{15}{28}\)
\(\Rightarrow x=\dfrac{15}{28}:\dfrac{5}{14}\)
\(\Rightarrow x=\dfrac{3}{2}\)
c) \(4x\cdot\left(x+\dfrac{3}{5}\right)=0\)
TH1: \(4x=0\)
\(\Rightarrow x=0\)
TH2: \(x+\dfrac{3}{5}=0\)
\(\Rightarrow x=-\dfrac{3}{5}\)
d) \(\left(\dfrac{5}{8}+x\right)\left(3x-\dfrac{6}{11}\right)=0\)
TH1: \(\dfrac{5}{8}+x=0\)
\(\Rightarrow x=-\dfrac{5}{8}\)
TH2: \(3x-\dfrac{6}{11}=0\)
\(\Rightarrow3x=\dfrac{6}{11}\)
\(\Rightarrow x=\dfrac{6}{11}:3\)
\(\Rightarrow x=\dfrac{2}{11}\)
