viết các số sau dưới dạng lũy thừa an
a) ( 4.2 )5 : \(\left(2^3.\dfrac{1}{16}\right)\)
b) \(\dfrac{2^2.4.32}{2^2.2^5}\)
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) \(\left(\dfrac{1}{3}\right)^2.\dfrac{1}{3}.9^2\)
a) \(3^3\)
b)\(2^8\)
c) \(2^7\)
d) \(3^1\)
a) 9.33.\(\dfrac{1}{81}\) .32 = 32. 33.\(\dfrac{1}{3^4}\) . 32 = 33
b) 4. 25: \(\) (23.\(\dfrac{1}{16}\))= 22. 25: 23. \(\dfrac{1}{2^4}\) = 27: \(\dfrac{1}{2}\) = 27. 2= 28
c) 32. 25. \(\left(\dfrac{2}{3}\right)^2\) = 32. 25. \(\dfrac{2^2}{3^2}\) = 25. 22 = 27
d) \(\left(\dfrac{1}{3}\right)^2\) .\(\dfrac{1}{3}\) . 92 = \(\dfrac{1}{9}.\dfrac{1}{3}\). 92 = \(\dfrac{9}{3}\) = 31
a không bít !
b chịu
c quên rồi
d . . .
14: \(\dfrac{9}{25}\) đc viết dưới dạng 1 lũy thừa, hãy cho bt cách viết nào sau đây là đúng:
A) \(\left(\dfrac{3}{5}\right)^2\) B) \(\left(\dfrac{-3}{5}\right)^2\) C) \(\dfrac{3^2}{5}\) D) cả a và b đều đúng
D, Vì 3^2=9 và -3^2=9 còn 5^2=25
Bài 1: viết các biểu thức dưới dạng lũy thừa. a/ 9.3^2.1/81.27. b/ 4.32:(2^3.1/16). c/ 3^4.3^5:1/27 d/ 2^2.4.32/(-2^2).2^5.
a/
\(9.3^2.\frac{1}{81}.27=\frac{9.3^2.27}{81}=\frac{3^2.3^2.3^3}{3^4}=\frac{3^7}{3^4}=3^3\)
b/
\(4.32:\left(2^3.\frac{1}{16}\right)=4.32:\left(\frac{2^3}{16}\right)=4.32:\left(\frac{2^3}{2^4}\right)=4.32:\frac{1}{2}=4.32.2=4.64=4.4^3=4^4\)
c/
\(3^4.3^5:\frac{1}{27}=3^4.3^5.27=3^4.3^5.3^3=3^{12}\)
d/(ý bạn là (-2)^2 hay -2^2 , mình làm theo cách (-2)^2 nhé!)
\(2^2.4.\frac{32}{\left(-2\right)^2}.2^5=2^2.2^2.\frac{2^5}{2^2}.2^5=2^2.2^2.2^3.2^5=2^{12}\)
Viết các biểu thức sau dưới dạng lũy thừa
a/ 9 x 32 x \(\frac{1}{81}\)x 27
b/ 4 x 32: (23 x \(\frac{1}{16}\))
c/34 x 35 :\(\frac{1}{27}\)
d/ \(\frac{2^2.4.32}{\left(-2\right)^2.2^5}\)
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) \(\dfrac{\left(\dfrac{1}{2}\right)^3.\dfrac{1}{2^2}.8}{\left(-2^3\right)^2.16}.\left(2^2\right)^3\)
a: \(=2^2\cdot9\cdot\dfrac{1}{6\cdot9}\cdot\dfrac{4^2}{9^2}=\dfrac{2^2}{6}\cdot\dfrac{2^4}{3^4}=\dfrac{2^6}{2\cdot3\cdot3^4}=\dfrac{2^5}{3^5}=\left(\dfrac{2}{3}\right)^5\)
b: \(=2^8\cdot\dfrac{3^4}{2^4}=3^4\cdot2^4=6^4\)
c: \(=\dfrac{\left(\dfrac{1}{2}\right)^3\cdot2^3\cdot\left(\dfrac{1}{2}\right)^2}{\left(-8\right)^2\cdot16}\cdot2^6=\dfrac{\dfrac{1}{2^2}}{64\cdot16}\cdot64=\dfrac{1}{4}:16=\dfrac{1}{64}=\left(\dfrac{1}{8}\right)^2\)
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) \(\dfrac{\left(\dfrac{1}{2}\right)^3.\dfrac{1}{2^2}.8}{\left(-2^3\right)^2.16}.\left(2^2\right)^3\)
a: \(=2^2\cdot9\cdot\dfrac{1}{3^3\cdot2}\cdot\dfrac{2^4}{3^4}=\dfrac{2^4\cdot2^2}{2}\cdot\dfrac{9}{3^3\cdot3^4}=\dfrac{2^5}{3^5}=\left(\dfrac{2}{3}\right)^5\)
b: \(=2^8\cdot\dfrac{3^4}{2^4}=3^4\cdot2^4=6^4\)
c: \(=\dfrac{\dfrac{1}{2^3}\cdot\dfrac{1}{2^2}\cdot8}{\left(-8\right)^2\cdot2^4}\cdot2^6=\dfrac{1}{2^2}\cdot2^6:2^{10}=\dfrac{2^4}{2^{10}}=\dfrac{1}{2^6}=\left(\dfrac{1}{8}\right)^2\)
c) \(\left(1\dfrac{1}{4}\right)^{10}\). \(\left(\dfrac{2}{5}\right)^{20}\)
Viết kết quả dưới dạng một lũy thừa
`(1 1/4)^10 . (2/5)^20`
`=(5/4)^10 . (2/5)^20`
`=(5^10 .2^20)/(4^10 .5^20)`
`=(5^10 .4^10)/(4^10 .5^20)`
`=1/(5^10)`
`=(1/5)^10`
Viết số\(\dfrac{16}{81}\) dưới dạng một lũy thừa, ví dụ \(\dfrac{16}{81}=\left(\dfrac{4}{9}\right)^2\). Hãy tìm cách viết khác
\(\dfrac{16}{81}=\left(\dfrac{2}{3}\right)^4\)
\(\dfrac{16}{81}=\left(-\dfrac{4}{9}\right)^2\)
\(\dfrac{16}{81}=\left(\dfrac{2}{3}\right)^4\)
Viết dưới dạng lũy thừa của 1 số nguyên
a)\(12^3:\left(3^{-4}.64\right)\) b) \(\left(\dfrac{3}{7}\right)^5.\left(\dfrac{7}{3}\right)^{-1}.\left(\dfrac{5}{3}\right)^6:\left(\dfrac{343}{625}\right)^{-2}\)c) \(5^4.125.\left(2,5\right)^{-5}.0,04\)
a: \(=\dfrac{3^3\cdot2^6}{3^{-4}\cdot2^6}=3^7\)
b: \(=\left(\dfrac{3}{7}\right)^5\cdot\left(\dfrac{3}{7}\right)\cdot\dfrac{5^6}{3^6}:\left(\dfrac{625}{343}\right)^2\)
\(=\dfrac{3^6}{7^6}\cdot\dfrac{5^6}{3^6}:\dfrac{5^8}{7^6}\)
\(=\dfrac{1}{5^2}\)
c: \(=5^{4+3}\cdot\left(\dfrac{5}{2}\right)^{-5}\cdot\dfrac{1}{25}\)
\(=5^5\cdot\left(\dfrac{2}{5}\right)^5=2^5\)