\(\dfrac{3}{7}+\dfrac{1}{7}:x=\dfrac{3}{14}\)
\(\Rightarrow\dfrac{1}{7}:x=\dfrac{3}{14}-\dfrac{3}{7}\)
\(\Rightarrow\dfrac{1}{7}:x=-\dfrac{3}{14}\)
\(\Rightarrow x=\dfrac{1}{7}:\dfrac{-3}{14}\)
\(\Rightarrow x=-\dfrac{14}{21}\)
\(\Rightarrow x=-\dfrac{2}{3}\)
Sửa hộ tui từ dòng 2 nha:=))
`1/7 : x = 3/14 - 3/7`
`1/7 : x = -3/14`
`x = -3/14 : 1/7`
`x = -2/3`
Vậy..