Tìm số hữu tỷ x, biết rằng:
a. (2x - 1)^4 = 81
b.(x - 1)^5 =-32
c. (2x - 1)^6 = (2x - 1)^8
Tìm số hữu tỷ x biết:
a, (2x-1)6= (2x-1)8
b, 5x + 5x+2= 650
a, (2x-1)^6= (2x-1)^8
=>2x-1=1 hoặc 2x-1=0
2x=2 hoặc 2x=1
x=1 hoặc x=1/2
b, 5^x + 5^x+2= 650
5x+5x.52=650
5x(1+52)=650
5x.26=650
5x=650:26
5x=25
5x=52
=>x=2
b, 5^x + 5^x+2 = 650
5^x ( 1 + 5^2) = 650
5^x . 26 = 650
5^x =650:26
5^x = 25
5^x = 5^2
x = 2
Bài 1: Tìm số hữu tỉ x biết:
a, ( 2x - 1 )4 = 81 b, ( x - 1 )5 = -32
c, ( 2x - 1 )6 = ( 2x - 1 )8
Bài 2: Tìm các số tự nhiên x, y biết rằng:
a, 2x + 1 . 3y = 12x. b, 10x : 5y = 20y
c, 2x = 4y - 1 và 27y = 3x + 8
Bài 2:
a: Ta có: \(2^{x+1}\cdot3^y=12^x\)
\(\Leftrightarrow2^{x+1}\cdot3^y=2^{2x}\cdot3^x\)
\(\Leftrightarrow\left\{{}\begin{matrix}x+1=2x\\x=y\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=1\\y=1\end{matrix}\right.\)
tìm x thuộc n biết
A. 3\(^x\)=81x3
b.2\(^{x+1}\)=32
c. 3\(^{x+2}\):27=3
d. 2x2=32
e. (2x-1)4=81
f. (2x-6)4=0
a: =>3^x=3^4*3=3^5
=>x=5
b: =>\(2^{x+1}=2^5\)
=>x+1=5
=>x=4
c: \(\Leftrightarrow3^{x+2-3}=3\)
=>x-1=1
=>x=2
d: \(\Leftrightarrow x^2=\dfrac{32}{2}=16\)
=>x=4 hoặc x=-4
e: (2x-1)^4=81
=>2x-1=3 hoặc 2x-1=-3
=>2x=4 hoặc 2x=-2
=>x=-1 hoặc x=2
f: (2x-6)^4=0
=>2x-6=0
=>x-3=0
=>x=3
a) \(3^x=81\cdot3\)
\(\Rightarrow3^x=3^4\cdot3\)
\(\Rightarrow3^x=3^5\)
\(\Rightarrow x=5\)
b) \(2^{x+1}=32\)
\(\Rightarrow2^{x+1}=2^5\)
\(\Rightarrow x+1=5\)
\(\Rightarrow x=4\)
c) \(3^{x+2}:27=3\)
\(\Rightarrow3^{x+2}:3^3=3\)
\(\Rightarrow3^{x+2-3}=3\)
\(\Rightarrow3^{x-1}=3\)
\(\Rightarrow x-1=1\)
\(\Rightarrow x=2\)
d) \(2x^2=32\)
\(\Rightarrow x^2=16\)
\(\Rightarrow x^2=4^2\)
\(\Rightarrow\left[{}\begin{matrix}x=4\\x=-4\end{matrix}\right.\)
e) \(\left(2x-1\right)^4=81\)
\(\Rightarrow\left(2x-1\right)^4=3^4\)
\(\Rightarrow\left[{}\begin{matrix}2x-1=3\\2x-1=-3\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}2x=4\\2x=-2\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=2\\x=-1\end{matrix}\right.\)
f) \(\left(2x-6\right)^4=0\)
\(\Rightarrow2x-6=0\)
\(\Rightarrow2x=6\)
\(\Rightarrow x=6:2\)
\(\Rightarrow x=3\)
\(a,3^x=81\cdot3\\ \Leftrightarrow3^x=3^4\cdot3\\ \Leftrightarrow3^x=3^5\\ \Leftrightarrow x=5\\ d,2^{x+1}=32\\ \Leftrightarrow x+1=5\\ \Leftrightarrow x=4\\ c,3^{x+2}:27=3\\ \Leftrightarrow3^{x+2}:3^3=3\\ \Leftrightarrow3^{x-1}=3\\ \Leftrightarrow x-1=1\\ \Leftrightarrow x=2\\ d,2x^2=32\\ \Leftrightarrow x^2=16\\ \Leftrightarrow\left[{}\begin{matrix}x=4\\x=-4\end{matrix}\right.\\ e,\left(2x-1\right)^4=81\\ \Leftrightarrow\left[{}\begin{matrix}2x-1=3\\2x-1=-3\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=2\\x=-1\end{matrix}\right.\\ f,\left(2x-6\right)^4=0\\ \Leftrightarrow2x-6=0\\ \Leftrightarrow x=3\)
Tìm số hữu tỉ x, biết rằng:
(2x-1)^6 =(2x-1)^8
Các giá trị x thu được là \(0,1,\frac{1}{2}\)
\(\left(2x-1\right)^6=\left(2x-1\right)^8\)
\(\Leftrightarrow\left(2x-1\right)^6-\left(2x-1\right)^8=0\)
\(\Leftrightarrow\left(2x-1\right)^6.[1-\left(2x-1\right)^2]=0\)
\(\Leftrightarrow\orbr{\begin{cases}\left(2x-1\right)^6=0\\1-\left(2x-1\right)^2=0\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}2x-1=0\\\left(2x-1\right)^2=1\end{cases}}\)
Còn bn tự giải nhé
Tìm số hữu tỉ x , biết rằng :
( 2x - 1 )6 = ( 2x - 1 )8
( 2 - 3x )4 : (3x-2 )5
(2x-1)^6=(2x-1)^8'
=> (2x-1)=1 hoặc (2x-1)=0
(2x-1)=1 =>2x=2 =>x=1
(2x-1)=0 =>2x=1 =>x=0,5
\(\left(2x-1\right)^6=\left(2x-1\right)^8\)
\(\left(2x-1\right)^6-\left(2x-1\right)^8=0\)
\(\left(2x-1\right)^6-\left(2x-1\right)^6.\left(2x-1\right)^2=0\)
\(\left(2x-1\right)^6.\left[1-\left(2x-1\right)^2\right]=0\)
\(\left(2x-1\right)^6.\left[\left(1-2x+1\right)\left(1+2x-1\right)\right]=0\)
\(\left(2x-1\right)^6.\left[\left(2-2x\right).2x\right]=0\)
\(\left(2x-1\right)^6.\left[4x\left(1-x\right)\right]=0\)
\(\Rightarrow\orbr{\begin{cases}\left(2x-1\right)^6=0\\4x\left(1-x\right)=0\end{cases}}\Rightarrow\orbr{\begin{cases}2x-1=0\\4x=0hoac1-x=0\end{cases}}\Rightarrow\orbr{\begin{cases}x=\frac{1}{2}\\x=0hoacx=1\end{cases}}\)
vay \(x=\frac{1}{2}\)hoac \(\orbr{\begin{cases}x=0\\x=1\end{cases}}\)
\(\frac{\left(2-3x\right)^4}{\left(3x-2\right)^5}=\frac{-\left(3x-2\right)^4}{\left(3x-2\right)^5}=\frac{-1}{3x-2}\)
Giúp Mik với, tất cả bạn nào làm xong thì mik tick cho :DD
Bài 1: Tìm số hữu tỷ x biết rằng:
a) -3/2 - 2x + 3/4 = -2
b) (-2/3 . x - 3/5)(3/-2) = 2/5
c) x/2- (3x/5 - 13/5) = -(7/5 + 7/10 . x)
d) 2x - 3/3 + -3/2 = 5 - 3x/6 - 1/3
Tìm số nguyên x biết 125:x=2^2-(-1)
2x-8=-4
6^2x+5=216
a)125 : x = 22 - (-1)
125 : x = 4 + 1
125 : x = 5
x = 125 : 5
x = 25
-------------------------------------------------
b) 2x - 8 = -4
2x = (-4) + 8
2x = 4
x = 4 : 2
x = 2
-----------------------------------------------------------
c) Xem lại đề.
\(125:x=2^2-\left(-1\right)\)
\(=>125:x=4+1\)
\(=>125:x=5\)
\(=>x=125:5\)
\(=>x=25\)
_____
\(2x-8=-4\)
\(=>2x=\left(-4\right)+8\)
\(=>2x=4\)
\(=>x=4:2\)
\(=>x=2\)
_______
\(6^{2x+5}=216\)
\(=>6^{2x+5}=6^3\)
\(=>2x+5=3\)
\(=>2x=3-5\)
\(=>2x=-2\)
\(=>x=\left(-2\right):2\)
\(=>x=-1\)
\(#NqHahh\)
125:x=22 - (-1)
125:x=4+1
125:x=5
X=125:5
X=25
2x -8 = -4
2x=-4+8
2x=4
X=4:2
X=2
62(x+5) = 216
36(x+5) = 216
X+5 = 216:36
X+5=6
X=6-5
X=1
tìm x
a,3 4/5 : 8/5 = 0,25 :x
b, 2x+3/24 = 3x-1/32
c, 13x-2/2x+5=76/17
a) \(3\dfrac{4}{5}:\dfrac{8}{5}=0,25:x\)
\(\Rightarrow\dfrac{19}{5}.\dfrac{5}{8}=\dfrac{x}{4}\)
\(\Rightarrow\dfrac{x}{4}=2\Rightarrow x=8\)
b) \(2x+\dfrac{3}{24}=3x-\dfrac{1}{32}\)
\(\Rightarrow x=\dfrac{1}{8}+\dfrac{1}{32}=\dfrac{5}{32}\)
c) \(\dfrac{13x-2}{2x+5}=\dfrac{76}{17}\)
\(\Rightarrow221x-34=152x+380\)
\(\Rightarrow69x=414\Rightarrow x=6\)
Tìm số hữu tỉ x biết
\(\left(2x-1\right)^6=\left(2x-1\right)^8\)
giống cái kia thôi bn
Mik làm rồi mà
Mà cái bn Nguyễn Duy Đạt gì đó làm thiếu 1 trường hợp
Mà bn vẫn kik hở
Sao zzzzz??????
\(\left(2x-1\right)^6=\left(2x-1\right)^8\Leftrightarrow\left(2x-1\right)^6-\left(2x-1\right)^8=0\)
\(\Leftrightarrow\left[\left(2x-1\right)-\left(2x-1\right)\right]...=0\Leftrightarrow x=0\)
''...'' vế sau á :), ko chắc