\(1,x\cdot\dfrac{1}{5}=\dfrac{-19}{4}+\dfrac{3}{4}\\ x\cdot\dfrac{1}{5}=-4\\ x=-4:\dfrac{1}{5}\\ x=-20\\ 2,\dfrac{-25}{4}:x=\dfrac{-1}{4}-\dfrac{1}{2}\\ \dfrac{-25}{4}:x=\dfrac{-3}{4}\\ x=\dfrac{-25}{4}:\dfrac{-3}{4}\\ x=\dfrac{-25}{-3}=\dfrac{25}{3}\)
\(x\dfrac{1}{5}-\dfrac{3}{4}=\dfrac{-19}{4}\\ =>x\dfrac{1}{5}=\dfrac{-19}{4}+\dfrac{3}{4}\\ =>x\dfrac{1}{5}=\dfrac{-16}{4}\\ =>x\dfrac{1}{5}=-4\\ x=-4:\dfrac{1}{5}\\ x=-20\)
Câu 2 làm tương tự.
\(1.x.\dfrac{1}{5}-\dfrac{3}{4}=\dfrac{-19}{4}\\ x.\dfrac{1}{5}=\dfrac{-19}{4}+\dfrac{3}{4}=-4\\ x=-4:\dfrac{1}{5}=-25\\ 2.\dfrac{-25}{4}:x+\dfrac{1}{2}=\dfrac{-1}{4}\\ x+\dfrac{1}{2}=\dfrac{-25}{4}:\dfrac{-1}{4}=25\\ x=25-\dfrac{1}{2}=\dfrac{49}{2}\)
