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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 \(2^{x+1}\cdot3^{y}=12^{x}\)
=>\(2^{x+1}\cdot3^{y}=\left(2^2\cdot3\right)^{x}=2^{2x}\cdot3^{x}\)
=>\(\begin{cases}2x=x+1\\ y=x\end{cases}\Rightarrow\begin{cases}x=1\\ y=x=1\end{cases}\)
Bài 9,
62x73+36x33=36x73+36x27=36(73+27)=36x100=3600.
197-\([\)6x(5-1)2+20220\(]\):5=197-\([\)6x16+1\(]\):5=197-97:5=197-97/5=888/5.
Bài 10,
21-4x=13
=>4x=21-13=8
=>x=8:4=2.
30:(x-3)+1=45:43=42=16
=>30:(x-3)=16-1=15
=>x-3=30:15=2
=>x=2+3=5.
(x-1)3+5x6=38
=>(x-1)3+30=38
=>(x-1)3=38-30=8=23
=>x-1=2
=>x=3.
a,\(5^3.2-100:4+2^3.5\)
= 125 . 2 - 25 + 8 . 5
= 250 - 25 + 40
= 265
b, \(6^2:9+50.2-3^3.3\)
= 36 : 9 + 100 - 27 . 3
= 4 + 100 - 81
= 23
b) \(5^3\cdot2-100:4+2^3\cdot5\)
\(=125\cdot2-25+8\cdot5\)
\(=250-25+40\)
\(=225+40=265\)
c) \(6^2:9+50\cdot2+3^3-3\)
\(=36:9+100+27-3\)
\(=4+100+27-3\)
\(=104+27-3=131-3=128\)
d) \(3^2\cdot5+2^3\cdot10-81:3\)
\(=9\cdot5+8\cdot10-27\)
\(=45+80-27\)
\(=125-27=98\)
e) \(5^{13}:5^{10}-25\cdot2^2\)
\(=5^{13-10}-5^2\cdot2^2\)
\(=5^3-\left(5\cdot2\right)^2\)
\(=125-10^2\)
\(=125-100=25\)
f) \(20:2^2+5^9:5^8\)
\(=20:4+5^{9-8}\)
\(=5+5^1=5+5=10\)
g) \(100:5^2+7\cdot3^2\)
\(=10^2:5^2+7\cdot9\)
\(=\left(10:5\right)^2+63\)
\(=2^2+63=4+63=67\)
h) \(84:4+3^9:3^7+5^0\)
\(=21+3^{9-7}+1\)
\(=21+3^2+1\)
\(=21+9+1=30+1=31\)
i) \(29-\left[16+3\cdot\left(51-49\right)\right]\)
\(=29-\left[16+3\cdot2\right]\)
\(=29-\left[16+6\right]\)
\(=29-22=7\)
j) \(\left(15^{19}:5^{17}+3\right)\cdot0:7\)
\(=\left[\left(3\cdot5\right)^{19}:5^{17}+3\right]\cdot0\)
Vì số nào nhân cho 0 cũng bằng 0 nên giá trị biểu thức trên bằng 0
k) \(7^9:7^7-3^2+2^3\cdot5\)
\(=7^{9-7}-9+8\cdot5\)
\(=7^2-9+40\)
\(=49-9+40=40+40=80\)
l) \(1200:2+6^2\cdot2^1+18\)
\(=600+36\cdot2+18\)
\(=600+72+18\)
\(=600+\left(72+18\right)=600+90=690\)
m) \(5^9:5^7+70:14-20\)
\(=5^{9-7}+5-20\)
\(=5^2+5-20\)
\(25+5-20=30-20=10\)
Những câu sau mình làm sau nhé bạn!!!!!!!
A . 89 - ( 73 - x ) = 20
73 - x = 89 - 20
73 - x = 69
\(\Rightarrow\)x = 4
B .
Bài 2a:
Tìm x
5/3x + 2/3 = 1/4
5/3x = 1/4 - 2/3
5/3x = 3/12 - 8/12
5/3x = - 5/12
x = -5/12 : 5/3
x = -5/12 x 3/5
x = - 1/4
Vậy x = -1/ 4


