a) \(\left(\dfrac{3}{7}+\dfrac{1}{2}\right)^2=\left(\dfrac{6}{14}+\dfrac{7}{14}\right)^2=\left(\dfrac{13}{14}\right)^2=\dfrac{169}{196}\)
b) \(\left(\dfrac{3}{4}-\dfrac{5}{6}\right)^2=\left(\dfrac{9}{12}-\dfrac{10}{12}\right)^2=\left(-\dfrac{1}{12}\right)^2=\dfrac{1}{144}\)
c) \(\dfrac{5^4\cdot20^4}{25^5\cdot4^5}=\dfrac{5^4\cdot5^4\cdot2^8}{5^{10}\cdot2^{10}}=\dfrac{1}{100}\)
d) \(\left(\dfrac{-10^5}{3}\right)\cdot\dfrac{-6^4}{5}=\dfrac{5^5\cdot3^4\cdot2^9}{3\cdot5}=5^4\cdot3^3\cdot2^9=2880000\)
e) \(\left(1+\dfrac{2}{3}-\dfrac{1}{4}\right)\cdot\left(\dfrac{4}{5}-\dfrac{3}{4}\right)^2=\dfrac{17}{12}\cdot\dfrac{1}{400}=\dfrac{17}{4800}\)
f) \(2:\left(\dfrac{1}{2}-\dfrac{2}{3}\right)^3=2:\left(\dfrac{-1}{6}\right)^3=2:\dfrac{-1}{216}=-432\)
