7^2*(1/7)^3+9*2/21 решите пожалуйста:)
7² * (1/7)³ + 9*2/21 = 49/1 * 1/343 + 9/1 * 2 /21 = 1/7 + 18/21 = = 3/21 + 18/21 = 21/21 = 1