a) 7³ - 10³ = 343 - 1000 = -657
б) (-1)¹² - (-3)⁵ = 1 - (-243) = 1 + 243 = 244
в) 6 * (5/6)³ = 6 * (125/216) = (6 * 125) / 216 = 750 / 216 = 125 / 36 = 3 17/36
Ответ: a) -657; б) 244; в) 3 17/36.