So sanh: (\(\dfrac{1}{243}\))\(^9\) và (\(\dfrac{1}{83}\))\(^{13}\)
so sánh hai phân số:( \(\dfrac{1}{243}\))9 và (\(\dfrac{1}{83}\))13
`(1/243)^9 = [1/(3^5)]^9 = [(1/3)^5]^9=(1/3)^13`
Vì: `1/3 > 1/83`
`=> (1/3)^13 > 1/(83)^13`.
so sanh phan so 1/2439 va 1/8313
1\243=1\(81.3)
(1\243)^9=1\((81^9.3^9)=1\(81^9.27^3)> 1\(81^9.81^3) >1\(83^12)>1\(83^13)
So sánh:
a, \(\left(\dfrac{1}{24}\right)^9\)và \(\left(\dfrac{1}{83}\right)^{13}\)
c, \(\dfrac{1}{5^{199}}\)và\(\dfrac{1}{3^{300}}\)
a) Vì \(\dfrac{1}{24}< \dfrac{1}{83}\)
⇒ \(\dfrac{1}{24^9}>\dfrac{1}{83^{13}}\)
a) \(\left(\dfrac{1}{24}\right)^9>\left(\dfrac{1}{27}\right)^9=\dfrac{1}{3^{27}}\)
\(\left(\dfrac{1}{83}\right)^{13}< \left(\dfrac{1}{81}\right)^{13}=\dfrac{1}{3^{52}}\)
Mà \(\dfrac{1}{3^{27}}>\dfrac{1}{3^{52}}\)
\(\Rightarrow\left(\dfrac{1}{24}\right)^9>\left(\dfrac{1}{83}\right)^{13}\)
b) \(3^{300}=\left(3^3\right)^{100}=27^{100}\)
\(5^{199}< 5^{200}=\left(5^2\right)^{100}=25^{100}\)
Mà \(25^{100}< 27^{100}\)
\(\Rightarrow5^{199}< 3^{300}\)
\(\Rightarrow\dfrac{1}{5^{199}}>\dfrac{1}{3^{300}}\)
\(a,\left(\dfrac{1}{24}\right)^9=\dfrac{1}{24^9};\left(\dfrac{1}{83}\right)^{13}=\dfrac{1}{83^{13}};24^9< 83^{13}\left(24< 83;9< 13\right)\\ \Rightarrow\dfrac{1}{24^9}< \dfrac{1}{83^{13}}\Rightarrow\left(\dfrac{1}{24}\right)^9< \left(\dfrac{1}{83}\right)^{13}\\ b,3^{300}=27^{100}>25^{100}=5^{200}>5^{199}\\ \Rightarrow\dfrac{1}{3^{300}}< \dfrac{1}{5^{199}}\)
so sanh hai phan so 1/2439 va1/8313
So Sánh : (1/243)^9 và (1/83)^13
\(\left(\frac{1}{243}\right)^9=\frac{1}{243^9}=\frac{1}{\left(3^5\right)^9}=\frac{1}{3^{45}}\)
\(\left(\frac{1}{83}\right)^{13}< \left(\frac{1}{81}\right)^{13}=\frac{1}{81^{13}}=\frac{1}{\left(3^4\right)^{13}}=\frac{1}{3^{52}}\)
Có \(3^{45}< 3^{52}\Rightarrow\frac{1}{3^{45}}>\frac{1}{3^{52}}\)
suy ra \(\left(\frac{1}{243}\right)^9>\left(\frac{1}{83}\right)^{13}\).
so sanh
\(\left(\frac{1}{243}\right)^9va\left(\frac{1}{83}\right)^{13}\)
so sánh
1/243 mũ 9 và 1/83 mũ 13
Ta có :
\(\frac{1}{243^9}=\frac{1}{\left(81.3\right)^9}=\frac{1}{81^9.27^3}>\frac{1}{81^9.81^3}=\frac{1}{81^{11}}>\frac{1}{8^{12}}>\frac{1}{8^{13}}\)
\(\Rightarrow\frac{1}{243^9}>\frac{1}{8^{13}}\)
so sánh \(\left(\dfrac{1}{243}\right)^9\)và \(\left(\dfrac{1}{84}\right)^{13}\)
so sánh 1 phần 243 tất cả mũ 9 và 1 phần 83 tất cả mũ 13
Ta có :
\(\frac{1}{243^9}=\frac{1}{\left(81.3\right)^9}=\frac{1}{81^9.27^3}>\frac{1}{81^9.81^3}=\frac{1}{81^{11}}>\frac{1}{8^{12}}>\frac{1}{8^{13}}\)
\(\Rightarrow\frac{1}{243^9}>\frac{1}{83^{13}}\)
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