[tex]\Big(3^{50}\cdot 9^{10}:81^{10}\Big):3^{30} = \Big(3^{50}\cdot \big(3^{2}\big)^{10}:\big(3^{4}\big)^{10}\Big):3^{30} = \\ \\ =\big(3^{50}\cdot3^{2\cdot10}:3^{4\cdot 10}\big):3^{30} = \big(3^{50}\cdot 3^{20}:3^{40}\big) : 3^{30} = \\ \\ =3^{50+20-40}:3^{30} = 3^{30}:3^{30} = 3^{30-30} = 3^{0} = 1[/tex]