\(\dfrac{1}{7}:x=\dfrac{3}{14}-\dfrac{3}{7}\\ =>\dfrac{1}{7}:x=\dfrac{3-3\times2}{14}\\ =>\dfrac{1}{7}:x=-\dfrac{3}{14}\\ =>x=\dfrac{1}{7}:\left(-\dfrac{3}{14}\right)\\ =>x=-\dfrac{2}{3}\)
\(\dfrac{3}{7}+\dfrac{1}{7}:x=\dfrac{3}{14}\)
\(\dfrac{1}{7}:x=\dfrac{3}{14}-\dfrac{3}{7}\)
\(\dfrac{1}{7}:x=-\dfrac{3}{14}\)
\(x=\dfrac{1}{7}:\left(-\dfrac{3}{14}\right)\)
\(x=-\dfrac{2}{3}\)