Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Ta có:
\(\left(\frac{1}{2}\right)^{225}=\left[\left(\frac{1}{2}\right)^9\right]^{25}=\left(\frac{1}{516}\right)^{25}\)
\(\left(\frac{1}{3}\right)^{100}=\left[\left(\frac{1}{3}\right)^4\right]^{25}=\left(\frac{1}{81}\right)^{25}\)
\(\frac{1}{516}< \frac{1}{81}\Rightarrow\left(\frac{1}{516}\right)^{25}< \left(\frac{1}{81}\right)^{25}\Rightarrow\left(\frac{1}{2}\right)^{225}< \left(\frac{1}{3}\right)^{100}\)
\(\frac{2008}{2009};\frac{20}{19}\)
\(1-\frac{2008}{2009}=\frac{1}{2009}\)
\(1-\frac{20}{19}=\frac{-1}{19}=\frac{1}{19}\)
Vì 19 < 2009 Nên \(\frac{1}{2009}< \frac{1}{19}\)
Vậy \(\frac{2008}{2009}>\frac{20}{19}\)
a: \(\Leftrightarrow3^n:27^n=\dfrac{1}{9}\)
\(\Leftrightarrow\left(\dfrac{1}{9}\right)^n=\dfrac{1}{9}\)
hay n=1
b: \(\Leftrightarrow3^n\cdot3^2=3^8\)
=>n+2=8
hay n=6
c: \(\Leftrightarrow2^n\cdot\dfrac{9}{2}=9\cdot2^5\)
\(\Leftrightarrow2^n=2^6\)
hay n=6
d: \(\Leftrightarrow8^n=512\)
hay n=3
mk chỉ biết câu a thôi
\(-3+\frac{1}{3}\)=\(\frac{-3}{1}\)+\(\frac{1}{3}\)= \(\frac{-9}{3}\)+\(\frac{1}{3}\)=\(\frac{-8}{3}\)
Bài 1:
= \(\frac{-8}{3}\)
= \(\frac{-9}{4}\)
= \(\frac{-42}{19}\)
Bài 2:
A = \(\frac{3}{7}\)
Ai thấy mình đúng tk nha !
B. 1/3 - 1/3 - 3/5 +3/5 + 5/7 - 5/7 + 9/11 - 9/11 -11/13 + 11/ 13 + 7/9 + 13/15
= 0 -0-0-0-0+7/9 +13/15
= 74/45
Xét \(\frac{1}{\sqrt{13}}>\frac{1}{\sqrt{14}}\Rightarrow\frac{1}{\sqrt{13}}-1< \frac{1}{\sqrt{14}}+1\)
Mà \(\sqrt{225}< \sqrt{289}\)
\(\Rightarrow\sqrt{225}-\left(\frac{1}{\sqrt{13}}-1\right)< \sqrt{289}-\left(\frac{1}{\sqrt{14}}+1\right)\)
Vậy....................
b)\(\frac{1}{330}< \frac{1}{225}\)vi day la truong hop cung tu
c)\(\frac{1}{3^{11}}=\frac{1}{177147}\)
\(\frac{1}{7^{14}}=1,474441139_{X10}^{12}\)
nen \(\frac{1}{3^{11}}< \frac{1}{7^{14}}\)vi day cung la truong hop cung tu
\(nha^{ }\)