А) (21/10 + 6/5) : 1/5 = (21/10 + 12/10): 1/5 = 33/10 * 5/1 = 33/2 = 16,5
б) 2/7 * (82/10 - 7/2) = 2/7 * (82/10 - 35/10) = 2/7 * 47/10 = 47/35
в) 2/15:(8 - 4/3) = 2/15:(24/3 - 4/3) = 2/15 * 20/3 = 1/50
г) (1/14 + 10/7):8/7 = (1/14 + 20/14):8/7 = 21/14 * 7/8 = 21/16 = 1 5/16
49⁶/7¹¹ = (7²)⁶ / 7¹¹ = 7¹²/7¹¹ = 7
81³/9⁴ = (9²)³/9⁴ = 9⁶/9⁴ = 9²=81
8⁵/2¹⁴ = (2³)⁵/2¹⁴ = 2¹⁵/2¹⁴=2
16⁵/4⁹ = (2³)⁵/2¹⁴ = 2¹⁵/2¹⁴ = 2