3^x-4.(3^2)^3=243
Những câu hỏi liên quan
a) 32x-1= 243 b) (3x)2 :33= 1/243
c) 23x+2= 4x+5 d) 3x+1= 9x
a) \(3^{2x-1}=243\)
\(\Leftrightarrow3^{2x-1}=3^5\)
\(\Leftrightarrow2x-1=5\)
\(\Leftrightarrow2x=5+1\)
\(\Leftrightarrow2x=6\)
\(\Leftrightarrow x=\dfrac{6}{2}\)
\(\Leftrightarrow x=3\)
Vậy \(x=3\)
b) \(\left(3^x\right)^2:3^3=\dfrac{1}{243}\)
\(\Leftrightarrow3^{2x}:3^3=\dfrac{1}{3^5}\)
\(\Leftrightarrow3^{2x}:3^3=3^{-5}\)
\(\Leftrightarrow3^{2x-3}=3^{-5}\)
\(\Leftrightarrow2x-3=-5\)
\(\Leftrightarrow2x=-5+3\)
\(\Leftrightarrow2x=-2\)
\(\Leftrightarrow x=-\dfrac{2}{2}\)
\(\Leftrightarrow x=1\)
Vậy \(x=1\)
c) \(2^{3x+2}=4^{x+5}\)
\(\Leftrightarrow2^{3x+2}=\left(2^2\right)^{x+5}\)
\(\Leftrightarrow2^{3x+2}=2^{2\left(x+5\right)}\)
\(\Leftrightarrow3x+2=2\left(x+5\right)\)
\(\Leftrightarrow3x+2=2x+10\)
\(\Leftrightarrow3x-2x=10-2\)
\(\Leftrightarrow x=8\)
Vậy \(x=8\)
d) \(3^{x+1}=9^x\)
\(\Leftrightarrow3^{x+1}=\left(3^2\right)^x\)
\(\Leftrightarrow3^{x+1}=3^{2x}\)
\(\Leftrightarrow x+1=2x\)
\(\Leftrightarrow2x-x=1\)
\(\Leftrightarrow x=1\)
Vậy \(x=1\)
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1/ 6^x-3=1
2/ 5^x-2=125
3/ 5^x-2=25
4/ 3^x+4=243
23 tháng 6 2023 lúc 14:32
a)\(3^{-1}\).\(4^x\)=\(\dfrac{5}{3}.2^7\)
b) \(9^{-x}\).\(27^x\)=243
a: =>4^x=640
=>\(x\in\varnothing\)
b: =>\(3^{-2x}\cdot3^{3x}=243\)
=>3^x=243
=>x=5
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Tìm x thuộc N biết
a) (3x)2 : 33= 243
b) 27 < 813 : 3x < 243
c) ( -3/4)3x-2 = 81/256
(3.x)^2 : 3^3=243
9.x^2 : 27=243
9.x^2=243.27
9.x^2=6561
x^2=6561:9
x^2=729
X=27
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giải phương trình
a) \(5^x=4\)
b) \(5^{2-x}=8\)
c) \(\left(\dfrac{1}{3}\right)^{4+x}=243\)
d) \(\left(\dfrac{2}{3}\right)^x=\dfrac{3}{2}\)
a: \(5^x=4\)
=>\(x=log_54\)
b: \(5^{2-x}=8\)
=>\(2-x=log_58\)
=>\(x=2-log_58\)
c: \(\left(\dfrac{1}{3}\right)^{x+4}=243\)
=>\(3^{-x-4}=3^5\)
=>-x-4=5
=>-x=9
=>x=-9
d: \(\left(\dfrac{2}{3}\right)^x=\dfrac{3}{2}\)
=>\(\left(\dfrac{2}{3}\right)^x=\left(\dfrac{2}{3}\right)^{-1}\)
=>x=-1
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Bài 2 Tìm x
b) |x+4/15|=-|-2,15|+|-3,75|
c) |3/4.x-3/4|-3/4=|-3/4|
d) (3^x)^2:3^3=1/243
e) 5^x.(5^3)^2=625
26 tháng 4 2022 lúc 20:26
Tìm x, biết:
a) \(\dfrac{x}{3}\) - 5 = \(\dfrac{2x}{5}\)
b) 4 + 3x = 8 - x
c) 2 . 3\(^{x+1}\) - 5 . 3\(^x\) = 243
a: =>1/3x-2/5x=5
=>-1/15x=5
=>x=-75
b: =>4x=4
=>x=1
c: =>6*3^x-5*3^x=243
=>3^x=243
=>x=5
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A.3^x=243 B.4^x=4096 C. 5^3-x=25 D.8^2x-3=512 E.2214-5.7^2x-3=499 J. 2^x+3+2^x+1=80
a: 3^x=243
=>3^x=3^5
=>x=5
b: 4^x=4096
=>4^x=4^5
=>x=5
c: 5^3-x=25
=>3-x=2
=>x=1
d: =>2x-3=3
=>2x=6
=>x=3
j: =>2^x*8+2^x*2=80
=>2^x=8
=>x=3
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x23:216=x15.x5(5x.5x+2):53=125(3x.3x+4):33=243715:713+2(x-5)=210:243x+3x+1+3x+2=243
Xem chi tiết
x23:216=x15.x5
x23: 63= x20
==> 63=x23:x20
==> 63=x3
==> x=6
(5x.5x+2):53=125
==> 52x+2:53=53
==> 52x+2=53.53
==> 52x+2=56
==> 2x+2=6
2x=6–2
2x=4
x=4:2
x=2
(3x.3x+4):33=243
==> 32x+4:33=35
32x+4=35.33
32x+4=38
==> 2x+4=8
2x=8–4
2x=4
x=4:2
x=2
3x+3x+1+3x+2=243
3x.1+3x.31+3x.32=243
3x.(1+31+32)=243
3x. (1+3+9)=243
3x.13=243
3x=243:13
3x=...
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