so sánh
2^91 và 5^35
107^50 và 73^75
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a)
Ta có 10750 = 1072x25 = (1072)25 = 1144925
7375 = 733x25 = (733)25 = 38901725
vì 11449 < 389017 nên 1144925 < 38901725
Do đó 10750 < 7375
b)
Ta có 291=(213)7=81927
535=(55)7=31257
Vì 81927>31257
Do đó 291>535
c)
Ta có 544 = (2.27)4 = (2.33)4 = 24.312
2112 = (7.3)12 = 712.312
Vì 712 > 212 > 24 -
Do đó 544 < 2112
a) 10750 và 7375
Ta có: 10750 < 12550 và 12550 = (53)50= 5150
7375 >2575 và 2575= (52)75= 5150
Ta có : 10750< 12550=2575<7375 suy ra 10750< 7375
Vậy 10750< 7375
b) 291 và 535
Ta có: 291 > 290 = (25)18= 3218
535<536 = (52)18 = 2518
Vì 32>25 và 18>0 nên
290>536>535. Mà 291> 290 nên 291> 535
c) Ta có: 544 < 604 = 154.44
2112>1512=154.158
Vì 164.44<154.158 nên 604< 1512 < 2112. Mà 604 > 56 4 nên 564 < 2112
Vập, 564 < 2112
\(107^{50}=107^{25.2}=\left(107^2\right)^{25}=11449^{25}\)
\(73^{75}=73^{3.25}=\left(73^3\right)^{25}=389017^{25}\)
Vì 11449<389017 => \(11449^{25}<389017^{25}\)
\(Hay: 107^{50}<73^{75}\)
a) Ta có: 10750 = 1072x25 = (1072)25 = 1144925
7375 = (733)25 = 38901725
Mà 11449 < 389017 nên 1144925 < 38901725
=> 10750 < 7375
b) Ta có: 291=(213)7= 81927
535 = (55)7 = 31257
Mà 81927>31257
=> 291>535
c) Ta có: 544 = (2.27)4 = (2.33)4 = 24.312
2112 = (7.3)12 = 712.312
Mà 712 > 212 > 24
=> 544 < 2112
Bài 1:
a: \(10^{10}=\left(2\cdot5\right)^{10}=2^{10}\cdot5^{10}=2^9\cdot5^{10}\cdot2\)
\(48\cdot50^5=2^4\cdot3\cdot\left(2\cdot5^2\right)^5=2^4\cdot3\cdot2^5\cdot5^{10}=2^9\cdot5^{10}\cdot3\)
mà 2<3
nên \(10^{10}<48\cdot50^5\)
b: \(1990^{10}+1990^9=1990^9\left(1990+1\right)=1990^9\cdot1991\)
\(1991^{10}=1991^9\cdot1991\)
mà 1990<1991
nên \(1990^{10}+1990^9<1991^{10}\)
c: \(107^{50}<108^{50}=\left(2^2\cdot3^3\right)^{50}=2^{100}\cdot3^{150}\)
\(73^{75}>72^{75}=\left(2^3\cdot3^2\right)^{75}=2^{225}\cdot3^{150}\)
mà \(2^{225}\cdot3^{150}>2^{100}\cdot3^{150}=108^{50}>107^{50}\)
nên \(73^{75}>107^{50}\)
d: \(2^{91}=\left(2^{13}\right)^7=8192^7\)
\(5^{35}=\left(5^5\right)^7=3125^7\)
mà 8192>3125
nên \(2^{91}>5^{35}\)
e: \(A=72^{45}-72^{44}=72^{44}\left(72-1\right)=72^{44}\cdot71\)
\(B=72^{44}-72^{43}=72^{43}\left(72-1\right)=72^{43}\cdot71\)
mà 44>43
nên A>B
Bài 2:
a:
ĐKXĐ: x<>2023
\(\frac{x-2023}{4}=\frac{1}{x-2023}\)
=>\(\left(x-2023\right)\left(x-2023\right)=4\cdot1\)
=>\(\left(x-2023\right)^2=4\)
=>\(\left[\begin{array}{l}x-2023=2\\ x-2023=-2\end{array}\right.\Rightarrow\left[\begin{array}{l}x=2+2023=2025\left(nhận\right)\\ x=-2+2023=2021\left(nhận\right)\end{array}\right.\)
b: \(\left(2x+1\right)^4=\left(2x+1\right)^6\)
=>\(\left(2x+1\right)^6-\left(2x+1\right)^4=0\)
=>\(\left(2x+1\right)^4\cdot\left\lbrack\left(2x+1\right)^2-1\right\rbrack=0\)
=>\(\left(2x+1\right)^4\cdot\left(2x+1-1\right)\left(2x+1+1\right)=0\)
=>\(2x\left(2x+1\right)^4\cdot\left(2x+2\right)=0\)
=>\(\left[\begin{array}{l}2x=0\\ 2x+1=0\\ 2x+2=0\end{array}\right.\Rightarrow\left[\begin{array}{l}x=0\\ x=-\frac12\\ x=-1\end{array}\right.\)
c: \(\left(3x-1\right)^{10}=\left(3x-1\right)^{20}\)
=>\(\left(3x-1\right)^{20}-\left(3x-1\right)^{10}=0\)
=>\(\left(3x-1\right)^{10}\cdot\left\lbrack\left(3x-1\right)^{10}-1\right\rbrack=0\)
=>\(\left[\begin{array}{l}\left(3x-1\right)^{10}=0\\ \left(3x-1\right)^{10}-1=0\end{array}\right.\Rightarrow\left[\begin{array}{l}3x-1=0\\ \left(3x-1\right)^{10}=1\end{array}\right.\)
=>\(\left[\begin{array}{l}3x-1=0\\ 3x-1=1\\ 3x-1=-1\end{array}\right.\Rightarrow\left[\begin{array}{l}x=\frac13\\ x=\frac23\\ x=0\end{array}\right.\)
d: Sửa đề \(2^{x+1}\cdot3^{y}=12^{x}\)
=>\(2^{x+1}\cdot3^{y}=\left(2^2\cdot3\right)^{x}=2^{2x}\cdot3^{x}\)
=>\(\begin{cases}2x=x+1\\ y=x\end{cases}\Rightarrow\begin{cases}x=1\\ y=x=1\end{cases}\)
\(\text{b, 5^36 = (5^3)^12 = 125}^{12}\)
\(\text{ 11^24 = (11^2)^12}=121^{12}\)
\(\text{Vì }125^{12}>121^{12}=>5^{36}>11^{24}\)
\(\text{c, }107^{50}=\left(107^2\right)^{25}=11449^{25}\)
\(73^{75}=\left(73^3\right)^{25}=389017^{25}\)
\(\text{Vì }11449^{25}< 389017^{25}\)\(=>107^{50}< 73^{75}\)
Bài giải
Ta có :
\(2^{91}=2^{90}\cdot2=\left(2^3\right)^{30}\cdot2=8^{30}\cdot2>5^{30}\)
\(\Rightarrow\text{ }2^{91}>5^{30}\)
\(21^8=\left(21^2\right)^4=441^4>54^4\)
\(\Rightarrow\text{ }54^4< 21^8\)
\(108^{50}=\left(108^2\right)^{25}=11664^{25}\)
\(73^{75}=\left(73^3\right)^{25}=389017^{25}\)
\(\text{Vì }11664^{25}< 389017^{25}\text{ }\Rightarrow\text{ }108^{50}< 73^{75}\)
Bài giải
\(2^{91}=2^{90}\cdot2=\left(2^3\right)^{30}\cdot2=8^{30}\cdot2>5^{30}\)
\(\Rightarrow\text{ }2^{91}>5^{30}\)
\(21^8=\left(21^2\right)^4=441^4>54^4\)
\(\Rightarrow\text{ }54^4< 21^8\)
\(108^{50}=\left(108^2\right)^{25}=11664^{25}\)
\(73^{75}=\left(73^3\right)^{25}=389017^{25}\)
\(\text{Vì }11664^{25}< 389017^{25}\text{ }\Rightarrow\text{ }108^{50}< 73^{75}\)
\(a)\) Ta có :
\(107^{50}=\left(107^2\right)^{25}=11449^{25}\)
\(73^{75}=\left(73^3\right)^{25}=389017^{25}\)
Vì \(11449^{25}< 389017^{25}\) nên \(107^{50}< 73^{75}\)
Vậy \(107^{50}< 73^{75}\)
a) 2^91=(2^13)^7=8192^7
5^35=(5^5)^7=3125^7
Mà 8192>3125=>8192^7>3125^7
=>2^91>5^35
b) 107^50 < 108^50 = (4.27)^50 = (2^2.3^3)^50 = 2^100.3^150
73^75 > 72^75 = (8.9)^75 = (2^3.3^2)^75 = 2^225.3^150
Mà 107^50 < 108^50 = 2^100.3^150 < 2^225.3^150 = 72^75 < 73^75
=> 107^50 < 73^75
b,10750=(1072)25=1144925
7375=(733)25=38901725
38901725>1144925 =>10750<73757
vậy 10750<7375
a,291=(213)7=81927
535=(55)7=31257
81927>31257 =>291>535
vậy 291>535