Question

BT3: Tìm x, biết

1) \(\dfrac{5}{3}-x+\dfrac{1}{5}=\dfrac{-3}{10}\)

2) \(\dfrac{11}{12}-\left(\dfrac{2}{5}+x\right)=\dfrac{2}{3}\)

Answer 1

1) \(\dfrac{5}{3}-x+\dfrac{1}{5}=\dfrac{-3}{10}\\ x+\dfrac{1}{5}=\dfrac{5}{3}-\left(\dfrac{-3}{10}\right)\\ x+\dfrac{1}{5}=\dfrac{5}{3}+\dfrac{3}{10}\\ x+\dfrac{1}{5}=\dfrac{59}{30}\\ x=\dfrac{59}{30}-\dfrac{1}{5}\\ x=\dfrac{53}{30}\)

Answer 2

2) \(\dfrac{11}{12}-\left(\dfrac{2}{5}+x\right)=\dfrac{2}{3}\\ \dfrac{2}{5}+x=\dfrac{11}{12}-\dfrac{2}{3}\\ \dfrac{2}{5}+x=\dfrac{11}{12}-\dfrac{8}{12}\\ \dfrac{2}{5}+x=\dfrac{1}{4}\\ x=\dfrac{1}{4}-\dfrac{2}{5}\\ x=\dfrac{-3}{20}\)

Answer 3

Sửa lại câu 1 nha :

\(\dfrac{5}{3}-x+\dfrac{1}{5}=\dfrac{-3}{10}\\ \dfrac{5}{3}-x=\dfrac{-3}{10}-\dfrac{1}{5}\\ \dfrac{5}{3}-x=\dfrac{-1}{2}\\ x=\dfrac{5}{3}-\left(\dfrac{-1}{2}\right)\\ x=\dfrac{13}{6}\)