Ответ:а) 2a²x³ - ax³ - a⁴ - a²x³ + ax³ + 2a² = a²x³ - a⁴ + 2a²б) 5x ⋅ 2y² - 5x ⋅ 3xy - x²y + 6xy² = 10xy² - 15x²y - x²y + 6xy²