So sánh
\(\left(17^5\right)^2va17^{10}\)
\(2^{60}va4^{20}\)
\(5^{45}va25^{15}\)
So sánh
\(\left(17^5\right)^2va17^{10}\)
\(2^{60}va4^{20}\)
\(5^{45}va25^{15}\)
\(64^8va16^{12}\)
+) Ta có: (175)2 = 175.2 = 1710
Ta thấy: 1710 = 1710 => (175)2 = 1710
+) Ta có: 420 = (22)20 = 22.20 = 240
Ta thấy: 260 > 240 => 260 > 420
+) Ta có: 2515 = (52)15 = 52.15 = 530
Ta thấy: 545 > 530 => 545 > 2515
+) Ta có: 648 = (43)8 = 43.8 = 424
1612 = (42)12 = 42.12 = 424
Ta thấy: 424 = 424 => 648 = 1612
(175)2 = 175.2 = 1710
mà 1710 = 1710
Vậy (175)2 = 1710
260 = (22)30 = 430
mà 430 > 420
Vậy 260 > 420
So sánh:
60^5 và 15^10
\(\left(\frac{1}{20}\right)^7và\left(\frac{1}{5}\right)^9\)
60^5 và 15^10 ta có: 15^10= (15^2)^5= 225^5
=> 60^5 >15^10
1/20^7 và 1/5^9 ta có 20^7>5^9
=> 1/20^7 <1/5^9
Bài 1 : So sánh
\(\left(\frac{1}{10}\right)^{15}\) và \(\left(\frac{3}{10}\right)^{20}\)
Bài 2 : So sánh
A = \(\left(\frac{13^{15}+1}{13^{16}+1}\right)\) và B = \(\left(\frac{13^{16}+1}{13^{17}+1}\right)\)
Bài 1:
Ta có:
\(\left(\frac{1}{10}\right)^{15}=\left(\frac{1}{5}\right)^{3.5}=\left(\frac{1}{125}\right)^5\)
\(\left(\frac{3}{10}\right)^{20}=\left(\frac{3}{10}\right)^{4.5}=\left(\frac{81}{10000}\right)^5\)
Lại có:
\(\frac{1}{125}=\frac{80}{10000}< \frac{81}{10000}\Rightarrow\left(\frac{1}{125}\right)^5< \left(\frac{81}{10000}\right)^5\)
\(\Rightarrow\left(\frac{1}{10}\right)^{15}< \left(\frac{3}{10}\right)^{20}\)
Bài 2:
Ta có:
\(A=\frac{13^{15}+1}{13^{16}+1}\Rightarrow13A=\frac{13^{16}+13}{13^{16}+1}=1+\frac{12}{13^{16}+1}\)
\(B=\frac{13^{16}+1}{13^{17}+1}\Rightarrow13B=\frac{13^{17}+13}{13^{17}+1}=1+\frac{12}{13^{17}+1}\)
Mà \(\frac{12}{13^{16}+1}>\frac{12}{13^{17}+1}\)
\(\Rightarrow1+\frac{12}{13^{16}+1}>1+\frac{12}{13^{17}+1}\)
\(\Rightarrow13A>13B\Rightarrow A>B\)
thực hiện phép tính sau :
\(\left[\dfrac{\left(0,8\right)^5}{\left(0,4\right)^6}+\dfrac{2^{15}.9^4}{6^6.8^3}\right]:\dfrac{45^{10}.5^{20}}{7^{15}}\)
=\(\left[\dfrac{\left(0,4.2\right)^5}{\left(0,4\right)^6}+\dfrac{2^9.2^6.3^8}{\left(3.2\right)^6.2^9}\right]=\left[\dfrac{\left(0,4\right)^5.2^5}{\left(0,4\right)^6}+\dfrac{2^6.3^8}{3^6.2^6}\right]\)
=\(\left[\dfrac{2^5}{0,4}+3^2\right]\)
=\(\left[80+9\right]=89\)
\(\left[\dfrac{\left(2.0,4\right)^5}{0,4,0,4^5}+\dfrac{2^{15}.3^8}{3^6.2^6.2^9}\right]\div\dfrac{3^{20}.5^{30}}{3^{15}.5^{30}}\)
\(=\left[\dfrac{2^5.0.4^5}{0,4.0,4^5}+\dfrac{2^{15}.3^8}{3^6.2^{15}}\right]\div3^5\)
\(=\left[\dfrac{2^5}{0,4}+3^2\right]\div243\)
\(=80+\left(3^5\div3^2\right)\)
\(=80+3^3\)
\(=80+27\)
\(=107\)
1. Tìm x:
\(\left(\frac{4}{5}\right)^{2x+7}=\frac{625}{256}\)
2. So sánh:
\(a=15^{120}:25^{60}\)và \(b=2^{45}.2^{15}.4^{60}\)
\(a=\left(15^2\right)^{60}:25^{60}\)
\(a=225^{60}:25^{60}\)
\(a=\left(225:25\right)^{60}=9^{60}\)
\(b=2^{45}.2^{15}.2^{120}\)
\(b=2^{180}=8^{60}\)
vì \(8^{60}< 9^{60}\)nên b<a
1,\(\left(\frac{4}{5}\right)^{2x+7}=\left(\frac{4}{5}\right)^{-4}\)
\(\Rightarrow\)2x+7=-4
2x=-11
x=-5,5
so sánh
a) \(\left(17^5\right)\)và \(17^{10}\)
b) \(\left(98^4\right)^3\)và \(98^{15}\)
c) \(2^{60}\)và \(4^{20}\)
nhanh và đúng mik tick cho nha
a) 17^5 < 17^10
b) (98^4)^3 < 98^15
c) 2^60 > 4^20
So sánh:
\(\left(\dfrac{1}{10}\right)^{15}\)và \(\left(\dfrac{3}{10}\right)^{20}\)
Ta có:
\(\left(\dfrac{1}{10}\right)^{15}=\left(\left(\dfrac{1}{10}\right)^3\right)^5=\left(\dfrac{1}{1000}\right)^5\)
\(\left(\dfrac{3}{10}\right)^{20}=\left(\left(\dfrac{3}{10}\right)^4\right)^5=\left(\dfrac{81}{10000}\right)^5\)
Ta có: \(\left(\dfrac{1}{10}\right)^{15}=\left(\dfrac{1}{10}^3\right)^5=\left(\dfrac{1}{1000}\right)^5\)
\(\left(\dfrac{3}{10}\right)^{20}=\left(\dfrac{3}{10}^4\right)^5=\left(\dfrac{3}{10000}\right)^5\)
Vì \(\dfrac{1}{1000}>\dfrac{3}{10000}\) nên \(\left(\dfrac{1}{10}\right)^{15}>\left(\dfrac{3}{10}\right)^{20}\)
1. So sánh
a, 0,135 và 0,(135)
b, 2,1(467) và \(\frac{43}{20}\)
c, \(^{\left(0,\left(3\right)\right)^2}\)và \(\left(0,3\right)^2\)
d, \(\frac{16}{121}và\left(0,3\left(59\right)\right)^2\)
e, \(\sqrt{7}+\sqrt{15}và7\)
f, \(\sqrt{17}+\sqrt{5}+1và\sqrt{45}\)
1. So sánh \(\left(\frac{1}{5}\right)^{45}\)và \(\left(\frac{-1}{2}\right)^{60}\)
\(\left(\frac{1}{5}\right)^{45}=\frac{1}{5^{45}}\)
\(\left(\frac{-1}{2}\right)^{60}=\frac{1}{2^{60}}\)
Thấy 545=(53)15
260=(24)15
5^3=125>2^4=16
=> 5^45<2^60
=> 1/5^45>1/2^60