K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

4 tháng 7 2017

1.\(45^{10}.5^{30}=45^{10}.125^{10}=\left(45.125\right)^{10}=5625^{10}\)

2.a. \(\left(2x-1\right)^3=-8\Leftrightarrow\left(2x-1\right)^3=\left(-2\right)^3\)

\(\Leftrightarrow2x-1=-2\Leftrightarrow x=-\frac{1}{2}\)

b.\(\left(x+\frac{1}{2}\right)^2=\frac{1}{16}\Leftrightarrow\orbr{\begin{cases}x+\frac{1}{2}=\frac{1}{4}\\x+\frac{1}{2}=-\frac{1}{4}\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}x=-\frac{1}{4}\\x=-\frac{3}{4}\end{cases}}\)

c. \(\left(2x+3\right)^2=\frac{9}{121}\Leftrightarrow\orbr{\begin{cases}2x+3=\frac{3}{11}\\2x+3=-\frac{3}{11}\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}x=-\frac{15}{11}\\x=-\frac{18}{11}\end{cases}}\)

d.\(\left(3x-1\right)^3=-\frac{8}{27}=\left(-\frac{2}{3}\right)^3\)

\(\Leftrightarrow3x-1=-\frac{2}{3}\Leftrightarrow x=\frac{1}{9}\)

4.

a.\(99^{20}=\left(99^2\right)^{10}=9801^{10}\)

Do \(9801^{10}< 9999^{10}\Rightarrow99^{20}< 9999^{10}\)

b.\(3^{4000}=\left(3^2\right)^{2000}=9^{2000}\)

\(\Rightarrow3^{4000}=9^{2000}\)

c.\(2^{332}=\left(2^3\right)^{110}.2^2=8^{110}.4\)

\(3^{223}=\left(3^2\right)^{110}.3^3=\left(3^2\right)^{110}.9=9^{110}.9\)

Ta thấy \(4.8^{110}< 9.9^{110}\)

Vậy \(2^{332}< 3^{223}\)

15 tháng 11 2021

bạ tự là đi minh mới lớp 6 nhá

undefined

15 tháng 9 2023

a) Vì \(-45< -16\) nên \(\left(-\dfrac{45}{17}\right)^{15}< \left(\dfrac{-16}{17}\right)^{15}\)

b) Vì \(21< 23\) nên \(\left(-\dfrac{8}{9}\right)^{21}< \left(-\dfrac{8}{9}\right)^{23}\)

c) \(27^{40}=3^{3^{40}}=3^{120}\)

\(64^{60}=8^{2^{60}}=8^{120}\)

Vì \(3< 8\) nên \(3^{120}< 8^{120}\) hay \(27^{40}< 64^{60}\)

19 tháng 7 2019

bài 2

làm câu B;C nha

B)

\(27^3=\left(3^3\right)^3=3^9\)

\(9^5=\left(3^2\right)^5=3^{10}\)

vì \(10>9\)

\(=>9^5>27^3\)

C)

\(\left(\frac{1}{8}\right)^6=\left(\frac{1}{2^3}\right)^6=\frac{1^6}{2^{18}}=\frac{1}{2^{18}}\)

\(\left(\frac{1}{32}\right)^4=\left(\frac{1}{2^5}\right)^4=\frac{1^4}{2^{20}}=\frac{1}{2^{20}}\)

vì \(2^{18}< 2^{20}\)

\(=>\frac{1}{2^{18}}>\frac{1}{2^{20}}\)

\(=>\left(\frac{1}{8}\right)^6>\left(\frac{1}{32}\right)^4\)

19 tháng 7 2019

\(\text{A.}\frac{32^3.9^5}{8^3.6^6}=\frac{\left(2^5\right)^3.\left(3^2\right)^5}{\left(2^3\right)^3.\left(2.3\right)^6}=\frac{2^{15}.3^{10}}{2^9.2^6.3^6}=\frac{3^{10}}{3^6}=3^4=81\)

\(\text{B.}\frac{\left(5^5-5^4\right)^3}{50^6}=\frac{2500^3}{50^6}=\frac{\left(50^2\right)^3}{50^6}=\frac{50^6}{50^6}=1\)

Bài 2:

\(\text{A.Ta có:}\)

\(5^6=\left(5^3\right)^2=125^2\)

\(\left(-2\right)^{14}=2^{14}=\left(2^7\right)^2=128^2\)

Vì \(125< 128\)

\(\Rightarrow125^2< 128^2\)

\(\Rightarrow5^6< \left(-2\right)^{14}\)

\(\text{B.Ta có:}\)

\(9^5=\left(3^2\right)^5=3^{10}\)

\(27^3=\left(3^3\right)^3=3^9\)

Vì \(9< 10\)

\(\Rightarrow3^9< 3^{10}\)

\(\Rightarrow27^3< 9^5\)

\(\text{C.Ta có:}\)

\(\left(\frac{1}{8}\right)^6=\left[\left(\frac{1}{2}\right)^3\right]^6=\left(\frac{1}{2}\right)^{18}\)

\(\left(\frac{1}{32}\right)^4=\left[\left(\frac{1}{2}\right)^5\right]^4=\left(\frac{1}{2}\right)^{20}\)

Vì \(18< 20\)

\(\Rightarrow\left(\frac{1}{2}\right)^{18}< \left(\frac{1}{2}\right)^{20}\)

\(\Rightarrow\left(\frac{1}{8}\right)^6< \left(\frac{1}{32}\right)^4\)