\(\left(\dfrac{3}{7}+\dfrac{1}{2}\right)^2=\left(\dfrac{3\cdot2+7}{14}\right)^2=\left(\dfrac{13}{14}\right)^2=\dfrac{169}{196}\)
\(\left[\dfrac{6}{14}+\dfrac{7}{14}\right]^2=\left[\dfrac{13}{14}\right]^4=\dfrac{169}{196}\)
\(\left(\dfrac{3}{7}+\dfrac{1}{2}\right)^2=\left(\dfrac{13}{14}\right)^2=\dfrac{169}{196}\)