1. 直接写出下列各式的结果:
(1) $(-3)^{0}=$; (2) $5^{-2}=$; (3) $(-2)^{-3}=$;
(4) $(π + 3)^{0}=$; (5) $-(0.3)^{-4}=$; (6) $|-0.2|^{-5}=$.
(1) $(-3)^{0}=$; (2) $5^{-2}=$; (3) $(-2)^{-3}=$;
(4) $(π + 3)^{0}=$; (5) $-(0.3)^{-4}=$; (6) $|-0.2|^{-5}=$.
答案:1. (1)1 (2)$\frac{1}{25}$ (3)$-\frac{1}{8}$ (4)1 (5)$-\frac{10^{4}}{81}$ (6)$5^{5}$
2. 计算:
(1) $2^{-1}+2^{0}-(-\frac{1}{3})^{-2}$; (2) $(\frac{1}{2})^{-1}+(-2)^{0}-|-3|$;
(3) $(-1)^{2024}+(3-π)^{0}-(\frac{1}{2})^{-1}$; (4) $3^{3}× 3^{-2}÷ 3^{8}$;
(5) $2^{2}-2^{-2}+(-2)^{-2}$; (6) $(-\frac{1}{2})^{-1}-(5-π)^{0}+0.25^{4}× 4^{5}$;
(7) $-1^{-2022}-(-\frac{2}{3})^{-2}+(-2)^{-3}÷ 2^{-3}$; (8) $(-\frac{1}{3})^{-2}-|-2^{3}|+(π - 5)^{0}+4^{20}÷ 2^{42}$.
(1) $2^{-1}+2^{0}-(-\frac{1}{3})^{-2}$; (2) $(\frac{1}{2})^{-1}+(-2)^{0}-|-3|$;
(3) $(-1)^{2024}+(3-π)^{0}-(\frac{1}{2})^{-1}$; (4) $3^{3}× 3^{-2}÷ 3^{8}$;
(5) $2^{2}-2^{-2}+(-2)^{-2}$; (6) $(-\frac{1}{2})^{-1}-(5-π)^{0}+0.25^{4}× 4^{5}$;
(7) $-1^{-2022}-(-\frac{2}{3})^{-2}+(-2)^{-3}÷ 2^{-3}$; (8) $(-\frac{1}{3})^{-2}-|-2^{3}|+(π - 5)^{0}+4^{20}÷ 2^{42}$.
答案:2. (1)$-\frac{15}{2}$ (2)0 (3)0 (4)$\frac{1}{3^{7}}$ (5)4 (6)1 (7)$-\frac{17}{4}$ (8)$\frac{9}{4}$
解析:
(1) $2^{-1}+2^{0}-(-\frac{1}{3})^{-2}=\frac{1}{2}+1 - 9=-\frac{15}{2}$
(2) $(\frac{1}{2})^{-1}+(-2)^{0}-|-3|=2 + 1 - 3=0$
(3) $(-1)^{2024}+(3-π)^{0}-(\frac{1}{2})^{-1}=1 + 1 - 2=0$
(4) $3^{3}× 3^{-2}÷ 3^{8}=3^{3-2-8}=3^{-7}=\frac{1}{3^{7}}$
(5) $2^{2}-2^{-2}+(-2)^{-2}=4 - \frac{1}{4}+\frac{1}{4}=4$
(6) $(-\frac{1}{2})^{-1}-(5-π)^{0}+0.25^{4}× 4^{5}=-2 - 1 + (0.25×4)^{4}×4=-3 + 1×4=1$
(7) $-1^{-2022}-(-\frac{2}{3})^{-2}+(-2)^{-3}÷ 2^{-3}=-1 - \frac{9}{4}+(-\frac{1}{8})÷\frac{1}{8}=-1 - \frac{9}{4}-1=-\frac{17}{4}$
(8) $(-\frac{1}{3})^{-2}-|-2^{3}|+(π - 5)^{0}+4^{20}÷ 2^{42}=9 - 8 + 1 + (2^{2})^{20}÷ 2^{42}=2 + 2^{40}÷ 2^{42}=2 + \frac{1}{4}=\frac{9}{4}$
(2) $(\frac{1}{2})^{-1}+(-2)^{0}-|-3|=2 + 1 - 3=0$
(3) $(-1)^{2024}+(3-π)^{0}-(\frac{1}{2})^{-1}=1 + 1 - 2=0$
(4) $3^{3}× 3^{-2}÷ 3^{8}=3^{3-2-8}=3^{-7}=\frac{1}{3^{7}}$
(5) $2^{2}-2^{-2}+(-2)^{-2}=4 - \frac{1}{4}+\frac{1}{4}=4$
(6) $(-\frac{1}{2})^{-1}-(5-π)^{0}+0.25^{4}× 4^{5}=-2 - 1 + (0.25×4)^{4}×4=-3 + 1×4=1$
(7) $-1^{-2022}-(-\frac{2}{3})^{-2}+(-2)^{-3}÷ 2^{-3}=-1 - \frac{9}{4}+(-\frac{1}{8})÷\frac{1}{8}=-1 - \frac{9}{4}-1=-\frac{17}{4}$
(8) $(-\frac{1}{3})^{-2}-|-2^{3}|+(π - 5)^{0}+4^{20}÷ 2^{42}=9 - 8 + 1 + (2^{2})^{20}÷ 2^{42}=2 + 2^{40}÷ 2^{42}=2 + \frac{1}{4}=\frac{9}{4}$
3. 阅读材料:①1 的任何次幂都等于 1;②-1 的奇数次幂都等于 -1;③-1 的偶数次幂都等于 1;④任何不等于零的数的零次幂都等于 1.请探索使得等式 $(2x + 3)^{x + 2024}=1$ 成立的 $x$ 的值.
答案:3. 解:当$x + 2024 = 0$时,$x = -2024$,所以$2x + 3 = -4045 ≠ 0$,符合题意;当$2x + 3 = 1$时,$x = -1$,$1^{2023} = 1$,符合题意;当$2x + 3 = -1$时,$x = -2$,所以$x + 2024 = 2022$,$(-1)^{2022} = 1$,符合题意.综上所述,$x$的值是$-2$或$-1$或$-2024$.
解析:
解:当$x + 2024 = 0$时,$x = -2024$,此时$2x + 3 = 2×(-2024) + 3 = -4045 ≠ 0$,符合题意;
当$2x + 3 = 1$时,$2x = 1 - 3 = -2$,解得$x = -1$,此时$(2x + 3)^{x + 2024} = 1^{-1 + 2024} = 1^{2023} = 1$,符合题意;
当$2x + 3 = -1$时,$2x = -1 - 3 = -4$,解得$x = -2$,此时$x + 2024 = -2 + 2024 = 2022$,$(-1)^{2022} = 1$,符合题意。
综上所述,$x$的值是$-2$或$-1$或$-2024$。
当$2x + 3 = 1$时,$2x = 1 - 3 = -2$,解得$x = -1$,此时$(2x + 3)^{x + 2024} = 1^{-1 + 2024} = 1^{2023} = 1$,符合题意;
当$2x + 3 = -1$时,$2x = -1 - 3 = -4$,解得$x = -2$,此时$x + 2024 = -2 + 2024 = 2022$,$(-1)^{2022} = 1$,符合题意。
综上所述,$x$的值是$-2$或$-1$或$-2024$。