Tìm x thuộc N biết :
a) 2^x . 4 = 128
b) 2^x = 4 . 128
c) 3^x = 3^3 . 3^5
d) 2^x . ( 2^2 ) mũ 3 = ( 2^3 ) mũ 2
Tìm x thuộc N biết: a)(x mũ 54)mũ2 = x b)2 mũ x+3 + 2 mũ x=144 Bài 4:Tìm a,b thuộc N biết a) 2 mũ a + 124 =5b b)3 mũ a + 9b = 183 Bài 5:Cho A= 1+2+2 mũ 2+2 mũ 3+...+2 mũ 2010 và B=2 mũ 2011 - 1
b: Ta có: \(2^{x+3}+2^x=144\)
\(\Leftrightarrow2^x\cdot9=144\)
\(\Leftrightarrow2^x=16\)
hay x=4
a) (x ^ 54)^2 = x
x^108 = x
Để: x^108 = x
=> x=0 hoặc x=1
b) 2^x+3 +2^x =144
2^X . 2^3 + 2^x =144
2^x.( 2^3+1) =144
2^x. 9 =144
2^x =144:9
2^x = 16
=> 2^x = 2^4
-Vậy x = 4
Bài 1: Tìm x thuộc N, biết
a) x=x mũ 5
b)x mũ 4= x mũ 2
c)(x-1)mũ 3 = x-1
Bài 2: Tìm x
(2x -1) mũ 3= 1 mũ 3+ 2 mũ 3+3 mũ 3+ 4 mũ 3+ 5 mũ 3
Bài 1
a) \(x=x^5\)
\(x^5-x=0\)
\(x\left(x^4-1\right)=0\)
\(x=0\) hoặc \(x^4-1=0\)
* \(x^4-1=0\)
\(x^4=1\)
\(x=1\)
Vậy x = 0; x = 1
b) \(x^4=x^2\)
\(x^4-x^2=0\)
\(x^2\left(x^2-1\right)=0\)
\(x^2=0\) hoặc \(x^2-1=0\)
*) \(x^2=0\)
\(x=0\)
*) \(x^2-1=0\)
\(x^2=1\)
\(x=1\)
Vậy \(x=0\); \(x=1\)
c) \(\left(x-1\right)^3=x-1\)
\(\left(x-1\right)^3-\left(x-1\right)=0\)
\(\left(x-1\right)\left[\left(x-1\right)^2-1\right]=0\)
\(x-1=0\) hoặc \(\left(x-1\right)^2-1=0\)
*) \(x-1=0\)
\(x=1\)
*) \(\left(x-1\right)^2-1=0\)
\(\left(x-1\right)^2=1\)
\(x-1=1\) hoặc \(x-1=-1\)
**) \(x-1=1\)
\(x=2\)
**) \(x-1=-1\)
\(x=0\)
Vậy \(x=0\); \(x=1\); \(x=2\)
Cho A = 3 + 3 mũ 2 + 3 mũ 3 + 3 mũ 4 + ………..…….+ 3 mũ 100
Tìm x thuộc N biết 2 A + 3 = 3 mũ x
Hộ mik nha bak
Tìm x thuộc z
a ) x ( x+ 3)
a ) (x - 2 ) (5-3)=0
a)(x-1) (x mũ 2 +1)=0
Cho A = ( 5 m mũ 2 - 8 m mũ 2 - 9 m mũ 2 )( -n mũ 3 +4 n mũ 3)
bài 3 tìm x thuộc N
a. 4.(x-5)-2 mũ 3 = 2 mũ 4.3
b, 4. x mũ 3 + 15 = 271
(2x -3) mũ 2 = 169
Bài 3 :
a) 4.(x-5) - 2 3=24.3
4x-20-8=48
4x=76
x=19
b) 4.x3+15=271
4.x3=256
x3=64
=> x=4
c) ( 2x-3)2= 169
=> 2x-3= 13
2x=16
x=8
Chúc bạn học tốt !
4*(x-5) - 2^3 = 2^4*3
4*(x-5) - 8 = 16*3
4*(x-5) - 8 = 48
4*(x-5) = 48 + 8
4*(x-5) = 56
x- 5 = 56 : 4
x - 5 = 14
x = 14 + 5
x = 19
4*x^3 + 15 = 271
4*x^3 = 271 - 15
4*x^3 = 256
x^3 = 256 : 4
x^3 = 64
x^3 = 4^3
x = 4
Tìm số tự nhiên x biết :
a ) (3x - 2 mũ 4) . 7 mũ 3 = 2 . 7 mũ 4
b) 3 . 2 mũ x + 2 mũ x + 3 = 88
c) 3 mũ x + 3 - 3 mũ x = 234
d ) 2 mũ x + 2 mũ x + 1 + 2 mũ x + 2 + 2 mũ x + 3 - 480 = 0
e ) 15 < 2 mũ x < 67
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Bài 1: tìm x thuộc N, biết
a) 2 mũ x -64=2 mũ 6
b) 2 mũ x : 16 = 128
Bài 2:Số nào lớn hơn
a) A= 1+3+3 mũ 2+3 mũ 3 +3 mũ 4+3 mũ 5 +3 mũ 6 và B=3 mũ 7 -1
b) A=8 mũ 2 và B =2 mũ 6
c) A=3 mũ 5 và B = 2 mũ 8
Bài 1 :
a) 2x-64=26
=> 2x-26=26
2x=26+26 (26+6)
2x = 212
<=> x = 12
b) 2x:16=128
=> 2x.24 = 27
2x = 27:24 (27-4)
2x = 23
<=> x=3
Bài 2 :
b) A= 82 = (23)2 = 26
B= 26
=> A = B ( 26=26 )
c) A= 35 = 243
B = 28 = 256
=> A < B ( 243 < 256 )
tìm x , biết :
a, ( x mũ 3 - 4 x mũ 2 ) - ( x -4 ) = 0
b, x mũ 5 - 9x = 0
c, ( x mxu 3 - x mũ 2 ) mũ 2 - 4 x mũ 2 + 8x - 4 = 0
a/
\(x^3-4x^2-\left(x-4\right)=0\)
\(\Leftrightarrow x^2\left(x-4\right)-\left(x-4\right)=0\)
\(\Leftrightarrow\left(x-4\right)\left(x^2-1\right)=0\)
\(\Leftrightarrow\left(x-4\right)\left(x-1\right)\left(x+1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x-4=0\\x-1=0\\x+1=0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=4\\x=1\\x=-1\end{matrix}\right.\)
b/
\(x^5-9x=0\)
\(\Leftrightarrow x\left(x^4-9\right)=x\left(x^2-3\right)\left(x^2+3\right)=0\)
\(\Leftrightarrow x\left(x-\sqrt{3}\right)\left(x+\sqrt{3}\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=\sqrt{3}\\x=-\sqrt{3}\end{matrix}\right.\)
c/
\(\left(x^3-x^2\right)^2-4x^2+8x-4=0\)
\(\Leftrightarrow x^4\left(x-1\right)^2-4\left(x-1\right)^2=0\)
\(\Leftrightarrow\left(x-1\right)^2\left(x^4-4\right)=0\)
\(\Leftrightarrow\left(x-1\right)^2\left(x^2-2\right)\left(x^2+2\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x-1=0\\x^2-2=0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=1\\x=\pm\sqrt{2}\end{matrix}\right.\)
Tìm x thuộc N
a)2^x(2 mũ x):4=128
b)x^15(x mũ 15)=x
c)(2.x+1)^3(mũ 3)=125
a) 2x : 4 = 128
=> 2x = 512
=> 2x = 29
=> x = 9
b) x15 = x
=> x15 = x15
=> x = 1 hoặc 0
c) ( 2x + 1 )3 = 125
=> ( 2x + 1 )3 = 53
=> 2x + 1 = 5
=> 2x = 4
=> x = 2
a) 2x : 4 = 128
=> 2x = 128 . 4
=> 2x = 512
=> 2x = 29
=> x = 9
b) x15 = x
=> x15 = x15
=> x = 1 hoặc 0
c) ( 2x + 1 )3 = 125
=> ( 2x + 1 )3 = 53
=> 2x + 1 = 5
=> 2x = 5 - 1
=> 2x = 4
=> x = 4 : 2
=> x = 2