\(\left(\dfrac{1}{3}\right)^{50}.\left(-9\right)^{25}-\dfrac{2}{3}:4\)
=\(\left(\dfrac{1}{9}\right)^{25}.\left(-9\right)^{25}-\dfrac{1}{6}\)
=\(\left[\dfrac{1}{9}.\left(-9\right)\right]^{25}-\dfrac{1}{6}\)
= \(\left(-1\right)^{25}-\dfrac{1}{6}\)
= \(-1-\dfrac{1}{6}=\dfrac{-7}{6}\)
\(\left(\dfrac{1}{3}\right)^{50}\cdot\left(-9\right)^{25}-\dfrac{2}{3}:4\)
\(=\left[\left(\dfrac{1}{3}\right)^2\right]^{25}\cdot\left(-9\right)^{25}-\dfrac{1}{6}\)
\(=\left(\dfrac{1}{9}\right)^{25}\cdot\left(-9\right)^{25}-\dfrac{1}{6}\)
\(=\left[\dfrac{1}{9}\cdot\left(-9\right)\right]^{25}-\dfrac{1}{6}\)
\(=\left(-1\right)^{25}-\dfrac{1}{6}=-1-\dfrac{1}{6}=-\dfrac{7}{6}\)
\(\dfrac{1}{3^{50}}\cdot\left(-1\right)\cdot9^{25}\)-\(\dfrac{2}{3}\cdot\dfrac{1}{4}\)
=\(\dfrac{1}{3^{50}}\cdot\left(3^2\right)^{25}\cdot\left(-1\right)-\dfrac{1}{6}\)
=\(\dfrac{1}{3^{50}}\cdot3^{50}\cdot\left(-1\right)-\dfrac{1}{6}\)
=\(1\cdot\left(-1\right)-\dfrac{1}{6}\)
=(-1)-