14. (8 分)(2024·江都区月考)计算:
(1) $(m - 1)^3·(1 - m)^4 + (1 - m)^5·(m - 1)^2$;
(2) $(-a^2)^2·a^5 + a^{10}÷a - (-2a^3)^3$。
答案:14. 解:(1)原式$=(m - 1)^3 · (m - 1)^4 - (m - 1)^5 · (m - 1)^2 = (m - 1)^{3 + 4} - (m - 1)^{5 + 2} = (m - 1)^7 - (m - 1)^7 = 0$.
(2)原式$=a^4 · a^5 + a^{10 - 1} + 8a^9 = a^9 + a^9 + 8a^9 = 10a^9$.
15. (8 分)比较 $2^{-33}$,$3^{-22}$,$5^{-111}$ 的大小。(用“$>$”连接)
答案:15. 解:因为$2^{-333} = (2^{-3})^{111} = (\frac{1}{8})^{111}$,$3^{-222} = (3^{-2})^{111} = (\frac{1}{9})^{111}$,$5^{-111} = (5^{-1})^{111} = (\frac{1}{5})^{111}$,又因为$\frac{1}{5} > \frac{1}{8} > \frac{1}{9}$,所以$5^{-111} > 2^{-333} > 3^{-222}$.
16. (8 分)(1)已知 $2^a = 3$,$4^b = 5$,$8^c = 5$,求 $8^{a + c - 2b}$ 的值;
(2)已知 $8^m÷4^n = 16$,求 $(-3)^{3m - 2n}$ 的值。
答案:16. 解:(1)因为$4^b = 5$,$8^c = 5$,所以$4^b = 2^{2b} = 5$,$8^c = 2^{3c} = 5$,所以$8^{a + c - 2b} = 2^{3(a + c - 2b)} = 2^{3a} × 2^{3c} ÷ 2^{6b} = (2^a)^3 × 2^{3c} ÷ (2^{2b})^3 = 3^3 × 5 ÷ 5^3 = \frac{27}{25}$.
(2)因为$8^m ÷ 4^n = 2^{3m} ÷ 2^{2n} = 2^{3m - 2n} = 16 = 2^4$,所以$3m - 2n = 4$,
所以$(-3)^{3m - 2n} = (-3)^4 = 81$.
17. (8 分)若 $a^n = -\frac{1}{3}$,$b^{2n} = 2$($n$ 为正整数),求 $1 + (-ab)^{4n} + a^{3n}b^{6n}$ 的值。
答案:17. 解:因为$a^n = -\frac{1}{3}$,$b^{2n} = 2$($n$为正整数),所以$a^{4n} = \frac{1}{81}$,$a^{3n} = -\frac{1}{27}$,$b^{6n} = 8$,$b^{4n} = 4$,
所以$1 + (-ab)^{4n} + a^{3n}b^{6n} = 1 + \frac{1}{81} × 4 + (-\frac{1}{27}) × 8 = \frac{61}{81}$.