\(\left(\dfrac{3}{7}+\dfrac{1}{2}\right)^2=\left(\dfrac{6+7}{14}\right)^2=\dfrac{169}{196}\)
\(\left(\dfrac{3}{4}-\dfrac{5}{6}\right)^2=\left(\dfrac{9-10}{12}\right)^2=\dfrac{1}{144}\)
\(\dfrac{5^4\cdot20^4}{25^5\cdot4^5}=\dfrac{5^4\cdot5^4\cdot4^4}{5^{10}\cdot4^5}=\dfrac{1}{4\cdot5^2}\)
