2^6 x 27^5 - 4^2 x 81^2
16 x 3^8 + 2^6 x 9^3
bài 2 viết mỗi tích, thương sau dưới dạng luỹ thừa
a) 4^10 x 2^30 b) 9^25 x 27^4 x 81^3 c) 25^50 x 125^5 d) 64^3 x 4^8 x 16^4
e)3^8:3^6 ; 2^10:8^3 ; 12^7 :6^7 ; 31^5 ; 81^3
f) 5^8 : 25^2 ; 4^9:64^2 ; 2^25 : 32^4 ; 125^3 : 25^4
a, 410. 230=220.230=250
b,925.274.813= 350.312.312=374
Tương tự các câu khác....
a, 410.230 = (22)10.230 = 220.230 = 250
b, 925.274.813 = (32)25.(33)4.(34)3 = 350.312.312 = 374
c, 2550.1255 = (52)50.(53)5 = 5100.515 = 5115
d, 643.48.164 = (26)3.(22)8.(24)4 = 218.216.216 = 250
e, 38 : 36 = 32
210 : 83 = 210 : (23)3 = 210 : 29 = 2
127 : 67 = (12 : 6)7 = 27
@Dương Tuyết Mai
tìm x
2^5.x+2=8^9
2^7.x+4=32^12
2^6+5.x=16^9
3^3-2.x=27^13
4^-1-5.x=16^12
3^6-3.x=81^3
GIẢI RÕ RÀNG HỘ MIK NHA
a) 32.x+2=1342176728
32.x=134217728-2
32.x=134217726
x=134217726:32
x=4194303,938
Bài 2: Tìm số tự nhiên x,biết:
1, 2 mũ x = 4
2, 2 mũ x = 8
3, 2 mũ x = 16
4, 2 mũ x = 1
5, 3 mũ x = 9
6, 3 mũ x = 81
7, 3 mũ x = 27
8, 5 mũ x = 25
9, 5 mũ x = 125
10, 8 mũ x = 64
11, 3 mũ x + 1 = 3 mũ 2
12, 2 mũ 2 x + 1 = 2 mũ 7
13, 5 mũ x - 1 = 5 mũ 2
14, 5 mũ 2 x - 4 = 5 mũ 10
15, 6 x + 4 = 6 mũ 10
16, 2 mũ 2 x - 3 = 2 mũ 9
17, 7 mũ 2 x - 3 = 7 mũ 7
18, 8 mũ x - 2 = 1
19, 9 mũ x - 8 = 81
20, 10 mũ 2 x - 1 = 1000
Giúp mình với,mình đang cần gấp !!
Bài 1:
2\(x\) = 4
2\(^x\) = 22
\(x=2\)
Vậy \(x=2\)
Bài 2:
2\(^x\) = 8
2\(^x\) = 23
\(x=3\)
Vậy \(x=3\)
Bài 3
2\(^x\) = 16
2\(^x\) = 24
\(x=4\)
Vậy \(x=4\)
1.Viết các tích sau dưới dạng lũy thừa
a) 4^8 . 2^20 ; 9^12 . 27^5 . 81^4 ; 64^3 . 4^5 . 16^2
b) 25^20 . 125^4 ; x^7 . x^4 . x^3 ; 3^6 . 4^6
c) 8^4 . 2^3 . 16^2 ; 2^3 . 2^2 . 8^3 ; y . y^7
2.Tính giá trị lũy thừa sau
a) 2^2 ; 2^3 ; 2^4 ; 2^5 ; 2^6 ; 2^7 ; 2^8 ; 2^9 ; 2^10
b) 3^2 ; 3^3 ; 3^4 ; 3^5
c) 4^2 ; 4^3 ; 4^4
d) 5^2 ; 5^3 ; 5^4
3.Viết các thương sau dưới dạng lũy thừa
a) 4^9 : 4^4 ; 17^8 : 17^5 ; 2^10 : 8^2 ; 18^10 : 3^10 ; 27^5 : 81^3
b)10^6 : 100 ; 5^9 : 25^3 ; 4^10 : 64^3 ; 2^25 : 32^4 ; 18^4 : 9^4
1) a) 4⁸.2²⁰ = (2²)⁸.2²⁰
= 2¹⁶.2²⁰ = 2³⁶
-----------
9¹².27⁵.81³ = (3²)¹².(3³)⁵.(3⁴)⁴
= 3²⁴.3¹⁵.3¹⁶ = 3⁵⁵
--------
64³.4⁵.16² = (4³)³.4⁵.(4²)²
= 4⁹.4⁵.4⁴ = 4¹⁸
b) 25²⁰.125⁴ = (5²)²⁰.(5³)⁴
= 5⁴⁰.5¹² = 5⁵²
--------
x⁷.x³.x⁴ = x¹⁴
--------
3⁶.4⁶ = (3.4)⁶ = 12⁶
2) a) 2² = 4
2³ = 8
2⁴ = 16
2⁵ = 32
2⁶ = 64
2⁷ = 128
2⁸ = 256
2⁹ = 512
2¹⁰ = 1024
b) 3² = 9
3³ = 27
3⁴ = 81
3⁵ = 243
c) 4² = 16
4³ = 64
4⁴ = 256
d) 5² = 25
5³ = 125
5⁴ = 625
3)
a) 4⁹ : 4⁴ = 4⁵
17⁸ : 17⁵ = 17³
2¹⁰ : 8² = 2¹⁰ : (2³)² = 2¹⁰ : 2⁶ = 2⁴
18¹⁰ : 3¹⁰ = (18 : 3)¹⁰ = 6¹⁰
27⁵ : 81³ = (3³)⁵ : (3⁴)³ = 3¹⁵ : 3¹² = 3³
b) 10⁶ : 100 = 10⁶ : 10² = 10⁴
5⁹ : 25³ = 5⁹ : (5²)³ = 5⁹ : 5⁶ = 5³
4¹⁰ : 64³ = 4¹⁰ : (4³)³ = 4¹⁰ : 4⁹ = 4
2²⁵ : 32⁴ = 2²⁵ : (2⁵)⁴ = 2²⁵ : 2²⁰ = 2⁵
18⁴ : 9⁴ = (18 : 9)⁴ = 2⁴
1)2x+1×22014=22015
2)7x-2x=617:615+44:11
3)3x=9
4)7x-x=521:519+3×22-70
5)4x=64
6)9x-1=9
7)2x:25=1
8)(5x-9)3=216
9)5×37x-11=135
10)2×3x=19×38-812
1) \(2^{x+1}\cdot2^{2014}=2^{2015}\)\(\Leftrightarrow2^{2014x+2014}=2^{2015}\)\(\Leftrightarrow2014x+2014=2015\)\(\Leftrightarrow x=\frac{1}{2014}\)
2) \(7x-2x=\frac{6^{17}}{6^{15}}+\frac{44}{11}\)\(\Leftrightarrow5x=6^2+4=36+4=40\)\(\Leftrightarrow x=\frac{40}{5}=8\)
3) \(3^x=9\)\(\Leftrightarrow3^x=3^2\)\(\Leftrightarrow x=2\)
4) \(7x-x=\frac{5^{21}}{5^{19}}+3\cdot2^2-7^0\)\(\Leftrightarrow6x=5^2+3\cdot4-1=25+12-1=36\)\(\Leftrightarrow x=6\)
5) \(4^x=64\)\(\Leftrightarrow4^x=4^3\)\(\Leftrightarrow x=3\)
6) \(9^{x-1}=9\)\(\Leftrightarrow x-1=1\)\(\Leftrightarrow x=0\)
7) \(\frac{2^x}{2^5}=1\)\(\Leftrightarrow2^{x-5}=2^0\)\(\Leftrightarrow x-5=0\)\(\Leftrightarrow x=5\)
8) \(\left(5x-9\right)^3=216\)\(\Leftrightarrow\left(5x-9\right)^3=6^3\)\(\Leftrightarrow5x-9=6\)\(\Leftrightarrow5x=15\)\(\Leftrightarrow x=3\)
9) \(5\cdot3^{7x-11}=135\)\(\Leftrightarrow5.3^{7x-11}=5.3^3\)\(\Leftrightarrow3^{7x-11}=3^3\)\(\Leftrightarrow7x-11=3\)\(\Leftrightarrow7x=14\Leftrightarrow x=2\)
10) \(2.3^x=19\cdot3^8-81^2\)\(\Leftrightarrow2.3^x=19\cdot3^8-3^8=18.3^8=2.3^{11}\)\(\Leftrightarrow3^x=3^{11}\Leftrightarrow x=11\)
Đây là cách làm của mình. Bạn có thể chỉnh sửa tuỳ ý theo cách làm của bạn nhé ^^
Học tốt ^3^
Tính nhẩm
9 x 2 = ...... | 9 x 3 = ...... | 9 x 4 = ...... | 9 x 5 = ...... |
18 : 9 = ...... | 27 : 9 = ...... | 36 : 9 = ...... | 45 : 9 = ...... |
9 x 6 = ...... | 9 x 7 = ...... | 9 x 8 = ...... | 9 x 9 = ...... |
54 : 9 = ...... | 63 : 9 = ...... | 72 : 9 = ...... | 81 : 9 = ...... |
9 x 2 = 18 | 9 x 3 = 27 | 9 x 4 = 36 | 9 x 5 = 45 |
18 : 9 = 2 | 27 : 9 = 3 | 36 : 9 = 4 | 45 : 9 = 5 |
9 x 6 = 54 | 9 x 7 = 63 | 9 x 8 = 72 | 9 x 9 = 81 |
54 : 9 = 6 | 63 : 9 = 7 | 72 : 9 = 8 | 81 : 9 = 9 |
9 x 2 = 18 9 x 3 = 27 9 x 4 = 36 9 x 5 = 45
18 : 9 = 2 27 : 9 = 3 36 : 9 = 4 45 : 9 = 5
9 x 6 = 54 9 x 7 = 63 9 x 8 = 72 9 x 9 = 81
54 : 9 = 6 63 : 9 = 7 72 : 9 = 8 81 : 9 = 9
tính : 8^2 x 125 x 9^2 - 32 x 5^3 x 81 phần 20^3 x 3^4 - 6^8 x 5^4
\(\dfrac{8^2.125.9^2-32.5^3.81}{20^3.3^4-6^8.5^4}\)
\(=\dfrac{2^6.5^3.3^4-2^5.5^3.3^4}{4^3.5^3.3^4-2^8.3^8.5^4}\)
\(=\dfrac{2^6.5^3.3^4-2^5.5^3.3^4}{2^6.5^3.3^4-2^8.3^8.5^4}\)
\(=\dfrac{2^5.5^3.3^4\left(2-1\right)}{2^6.5^3.3^4\left(1-2^2.3^4.5\right)}\)
\(=\dfrac{2^5.5^3.3^4.1}{2^6.5^3.3^4\left(1-810\right)}\)
\(=\dfrac{1}{2.\left(-809\right)}\)
\(=-\dfrac{1}{1618}\)
4 mũ n = 4096
5 mũ n = 15625
4 mũ n-1 = 1024
6 mũ n +3 = 216
X mũ 2 = x mũ 3
3 mũ x-1 = 27
3 mũ x+1 = 9
6 mũ x + 1 = 36
3 mũ 2x+1=27
X mũ 50= x
Tìm STN n
a) \(4^n=4096\Rightarrow4^n=4^6\Rightarrow n=6\)
b) \(5^n=15625\Rightarrow5^n=5^6\Rightarrow n=6\)
c) \(6^{n+3}=216\Rightarrow6^{n+3}=6^3\Rightarrow n+3=3\Rightarrow n=0\)
d) \(x^2=x^3\Rightarrow x^3-x^2=0\Rightarrow x^2\left(x-1\right)=0\Rightarrow\left[{}\begin{matrix}x=0\\x-1=0\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}x=0\\x=1\end{matrix}\right.\)
e) \(3^{x-1}=27\Rightarrow3^{x-1}=3^3\Rightarrow x-1=3\Rightarrow x=4\)
f) \(3^{x+1}=9\Rightarrow3^{x+1}=3^2\Rightarrow x+1=2\Rightarrow x=1\)
g) \(6^{x+1}=36\Rightarrow6^{x+1}=6^2\Rightarrow x+1=2\Rightarrow x=1\)
h) \(3^{2x+1}=27\Rightarrow3^{2x+1}=3^3\Rightarrow2x+1=3\Rightarrow2x=2\Rightarrow x=1\)
i) \(x^{50}=x\Rightarrow x^{50}-x=0\Rightarrow x\left(x^{49}-1\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x=0\\x^{49}-1=0\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}x=0\\x^{49}=1=1^{49}\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}x=0\\x=1\end{matrix}\right.\)
4n = 4096
4n = 212
n = 12
5n = 15625
5n = 56
n = 6
6n+3 = 216
6n+3 = 23.33
6n+3 = 63
n + 3 = 3
4ⁿ = 4096
4ⁿ = 4⁶
n = 6 (nhận)
Vậy n = 6
--------------------
5ⁿ = 15625
5ⁿ = 5⁶
n = 6 (nhận)
Vậy n = 6
--------------------
4ⁿ⁻¹ = 1024
4ⁿ⁻¹ = 4⁵
n - 1 = 5
n = 6 (nhận)
Vậy n = 6
-------------------
6ⁿ⁺³ = 216
6ⁿ⁺³ = 6³
n + 3 = 3
n = 0 (nhận)
Vậy n = 0
--------------------
x² = x³
x³ - x² = 0
x(x² - 1) = 0
x = 0 (nhận) hoặc x² - 1 = 0
*) x² - 1 = 0
x² = 1
x = 1 (nhận) hoặc x = -1 (loại)
Vậy x = 0; x = 1
--------------------
3ˣ⁻¹ = 27
3ˣ⁻¹ = 3³
x - 1 = 3
x = 3 + 1
x = 4 (nhận)
Vậy x = 4
---------------------
3ˣ⁺¹ = 9
3ˣ⁺¹ = 3²
x + 1 = 2
x = 2 - 1
x = 1 (nhận)
Vậy x = 1
--------------------
6ˣ⁺¹ = 36
6ˣ⁺¹ = 6²
x + 1 = 2
x = 2 - 1
x = 1 (nhận)
Vậy x = 1
--------------------
3²ˣ⁺¹ = 27
3²ˣ⁺¹ = 3³
2x + 1 = 3
2x = 3 - 1
2x = 2
x = 1 (nhận)
Vậy x = 1
--------------------
x⁵⁰ = x
x⁵⁰ - x = 0
x(x⁴⁹ - 1) = 0
x = 0 (nhận) hoặc x⁴⁹ - 1 = 0
*) x⁴⁹ - 1 = 0
x⁴⁹ = 1
x = 1 (nhận)
Vậy x = 0; x = 1
tìm x biết
1) x=-1/2 + 3/4 2) x - 1/5 = 2/11 3) x - 5/6 = 16/42 + -8/56
4) x/5 = 5/6 + -19/30 5) |x| - 1/4 = 6/18 6)x = -1/2 +3/4
7) x/15 = 3/5 + -2/3 8)11/8 + 13/6 = 85/x 9) x - 7/8 = 13/12
10) x - -6/15 = 4/27 11) -\(\dfrac{-6}{12}\)+ x = 9/48 12) x - 4/6 = 5/25 + -7/15
1: x=3/4-1/2=3/4-2/4=1/4
2: x-1/5=2/11
=>x=2/11+1/5=21/55
3: x-5/6=16/42-8/56
=>x-5/6=8/21-4/28=5/21
=>x=5/21+5/6=15/14
4: x/5=5/6-19/30
=>x/5=25/30-19/30=6/30=1/5
=>x=1
5: =>|x|=1/3+1/4=7/12
=>x=7/12 hoặc x=-7/12
6: x=-1/2+3/4
=>x=3/4-1/2=1/4
11: x-(-6/12)=9/48
=>x+1/2=3/16
=>x=3/16-1/2=-5/16
1)x= 1/4
2)x= 2/11+ 1/5
x= 21/55
3)x - 5/6 = 5/21
x = 5/21+5/6
x = 15/14
4)x/5 = 5/6 + -19/30
x:5 = 1/5
x = 1/5.5
x = 1
5) |x| - 1/4 = 6/18
|x| = 6/18 - 1/4
|x| =7/12
⇒x= 7/12 hoặc -7/12
6)x = -1/2 +3/4
x= 1/4
7) x/15 = 3/5 + -2/3
x:15 = -1/15
x = -1/15. 15
x = -1
8)11/8 + 13/6 = 85/x
85/24 = 85/x
⇒ x = 24
9) x - 7/8 = 13/12
x = 13/12 + 7/8
x = 47/24
10)x - -6/15 = 4/27
x = 4/27 + (-6/15)
x = -34/135
11) -(-6/12)+x = 9/48
x= 9/48 - 6/12
x = -5/16
12) x - 4/6 = 5/25 + -7/15
x -4/6 = -4/15
x = -4/15 + 4/6
x = 2/5