\(a. \)
\(\dfrac{-32}{\left(-2\right)^n}=4\)
\(\Rightarrow\left(-2\right)^n=-32:4=-8\)
\(\Rightarrow\left(-2\right)^n=\left(-2\right)^3\)
\(\Rightarrow n=3\)
\(b.\)
\(\dfrac{8}{2^n}=2\)
\(\Rightarrow2^n=4\)
\(\Rightarrow2^n=2^2\)
\(\Rightarrow n=2\)
\(c.\)
\(\dfrac{16}{\left(-2\right)^n}=-8\)
\(\Rightarrow\left(-2\right)^n=-2\)
\(\Rightarrow n=1\)
\(\dfrac{\left(\dfrac{-5}{7}\right)^n}{\left(\dfrac{-5}{7}\right)^{n-1}}\left(n\ge1\right)\) Tính
b) \(\dfrac{\left(-\dfrac{1}{2}\right)^{2n}}{\left(-\dfrac{1}{2}\right)^n}\left(n\in N\right)\)
Tìm x biết :
a) \(x^2-3=1\)
b) \(2x^3+12=-4\)
c) \(\left(2x-3\right)^2=16\)
d) \(x:\left(\dfrac{-1}{2}\right)^1=\dfrac{-1}{2}\)
h) \(\left(\dfrac{1}{4}-x\right)^2=\dfrac{25}{16}\)
i) \(\left(x+\dfrac{1}{3}\right)^3=\dfrac{-1}{8}\)
k) \(\left(\dfrac{1}{2}-x\right)^2=1\)
Viết các biểu thức số sau dưới dạng \(a^n,\left(a\in\mathbb{Q},n\in\mathbb{N}\right)\) :
a) \(9.3^3.\dfrac{1}{81}.3^2\)
b) \(4.2^5:\left(2^3.\dfrac{1}{16}\right)\)
c) \(3^2.2^5.\left(\dfrac{2}{3}\right)^2\)
d) \(\left(\dfrac{1}{3}\right)^2.\dfrac{1}{3}.9^2\)
Bài 1: Tìm n \(\in\) Z biết:
\(e)3^{-1}.3^n+6.3^{n-1}=7.3^6\)
\(g)3^4< \dfrac{1}{9}.27^n< 3^{10}\)
\(h)25< 5^n:5< 625\)
Bài 2: Tìm x biết:
\(\dfrac{2.\left(\dfrac{-1}{2}\right).\left(\dfrac{2}{3}\right)^2-3.\left(\dfrac{-1}{2}\right)^2.\dfrac{2}{3}+1}{3.\left(\dfrac{-1}{2}\right)-\dfrac{2}{3}}\)
Help me !!!!!!!!!!!!! giúp mk vs các bn giỏi toán 
Mấy chế zô giải giùm tui câu này:
Cho \(A=\left(\dfrac{1}{2^2}-1\right)\left(\dfrac{1}{3^2}-1\right)\left(\dfrac{1}{4^2}-1\right).....\left(\dfrac{1}{2013^2}-1\right)\left(\dfrac{1}{2014^2}-1\right)\) và \(B=-\dfrac{1}{2}.\)
Hãy so sánh A và B.
Viết các biểu thức sau dưới dạng lũy thừa
a) \(2^2.9.\dfrac{1}{54}.\left(\dfrac{4}{9}\right)^2\)
b) \(2^3.2^5.\left(\dfrac{3}{2}\right)^4\)
c) \(\dfrac{\left(\dfrac{1}{2}\right)^3.\dfrac{1}{2^2}.8}{\left(-2^3\right)^2.16}.\left(2^2\right)^3\)
Viết các biểu thức sau dưới dạng lũy thừa
a) \(2^2.9.\dfrac{1}{54}.\left(\dfrac{4}{9}\right)^2\)
b) \(2^3.2^5.\left(\dfrac{3}{2}\right)^4\)
c) \(\dfrac{\left(\dfrac{1}{2}\right)^3.\dfrac{1}{2^2}.8}{\left(-2^3\right)^2.16}.\left(2^2\right)^3\)
Tìm \(x\in\mathbb{Q}\), biết rằng :
a) \(\left(x-\dfrac{1}{2}\right)^2=0\)
b) \(\left(x-2\right)^2=1\)
c) \(\left(2x-1\right)^3=-8\)
d) \(\left(x+\dfrac{1}{2}\right)^2=\dfrac{1}{16}\)
Tính
a) \(\left(-52\right)^3:13^3\)
b) \(\left(\dfrac{1}{2}\right)^{15}:\left(\dfrac{1}{4}\right)^6\)
c) \(\left(\dfrac{1}{9}\right)^{30}:\left(\dfrac{1}{3}\right)^{56}\)
d) \(\left(\dfrac{1}{8}\right)^5:\left(\dfrac{1}{16}\right)^3\)
