(9)原式 = (a - b)^(2n) * (a - b)^[2(n - 1) ] = (a - b)^(2n + 2n - 2) = (a - b)^(4n - 2)
(10)原式 = -7(ab)^18 + 5a^18b^18 = -7(ab)^18 + 5(ab)^18 = -2(ab)^18
(11)原式 = 4a^6a^3 + 9a^2a^7 - 64a^9 = 4a^9 + 9a^9 - 64a^9 = -51a^9
(2)原式 = x^(4+3+5) + x^12 + 4x^12 = x^12 + 5x^12 = 6x^12
(13)原式 = x^8 - 2x^(2 + 6) + x^8 = 2x^8 - 2x^8 = 0
(14)原式 = (-1)(-1)(-1)(a^9)*(a^3) * (a^3) = -a^18