Tìm x :
3 mũ x +3 mũ x+2=810
3 mũ x + 3 mũ x+ 2 bang 810
\(3^x+3^{x+2}=810\\ 3^x\left(1+3^2\right)=810\\ 3^x.10=810\\ 3^x=810:10\\ 3^x=81\)
\(\Rightarrow x=4\)
3 mũ x +3 mũ x-2 = 810 với x lớn hơn hoặc bằng 2
giải nhanh nha mn
3^x + 3^x-2 = 810.
3^x + 3^x.3^2 = 810
3^x . (1 + 3^2) = 810
3^x . 10 = 810
3^x = 81
3^x = 3^4
=> x = 4
Vậy x = 4 Xin 1 tích nha ahehe:)))
Mọi người giải giúp mình 2 bài dưới đây và nhớ ghi cách giải nữa nhé ^^ Mik sẽ tick cho :D
1.) 5 mũ (x +1) + 6 . 5 mũ (x+1) =875
2.) 3 mũ (x+1) + 3 mũ (x+3) = 810
Ai nhanh nhất mik tick cho vì mik cần gấp lắm :D
1)5x+1 + 6.5x+1 = 875
5x+1 ( 1+6 ) = 875
5x+1 . 7 = 875
5x+1 = 875 : 7
5x+1 = 125
5x+1 = 53
x+1 = 3
x = 3 - 1
x = 2
2)3x+1 + 3x+3 = 810
3x . 3 + 32 . 3x+1 = 810
3x . 3 + 9 . 3x . 3 = 810
3x .3 ( 1 + 9 ) = 810
3x+1 . 10 = 810
3x+1 = 810 : 10
3x+1 = 81
3x+1 = 34
x+1 = 4
x = 4-1
x = 3
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 \(x=0\); \(x=1\); \(x=2\)
Tìm x,y biết : +). 5 mũ 2x-3 - 2.5 mũ 8 = 3.5 mũ 8
+). (3x-2) - (2x +5) = -7
+). 5x - 13 = -49 - 4x.
+). x+ (x+1) + (x+2)+...+ (x+30) = 496
+). 3 mũ x + 3 mũ x+2 =810
+). 3xy + x + 3y =4
+). 2x/3 - 2/y = 1/3
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 \(x=4\)
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
Bo may la binh day k di hieu ashdbfgbgygygggydfsghuyfhdguuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu3
Tìm x thuộc N :
x mũ 2 - ( 6 mũ 2 - ( 8 mũ 2 - 9 x 7 ) mũ 3 - 7 x 5 ) mũ 3 - 5 x 3 ) mũ 3 = 1
Baif2: Tìm x
a. 3 mũ 2 . x + 2 mũ 3 . x =51
b. 6 mũ 2 . 2 - (84 - 3 mũ 2 . x): 7 = 69
c. (x + 1) mũ 2= 64
e. (x - 1) mũ 2 = (x - 1) mũ 3
d. (2x + 1) mũ 3 = 27
g. 3 mũ x +2 =81
a) \(3^2.x+2^3.x=51\)
\(\Leftrightarrow x\left(3^2+2^3\right)=51\)
\(\Leftrightarrow17x=51\)
\(\Leftrightarrow x=3\)
Vậy
b) \(6^2.2-\left(84-3^2.x\right):7=69\)
\(\Leftrightarrow\left(84-3^2.x\right):7=3\)
\(\Leftrightarrow84-3^2.x=21\)
\(\Leftrightarrow3^2.x=63\)
\(\Leftrightarrow x=7\)
Vậy
c) \(\left(x+1\right)^2=64\)
\(\Leftrightarrow\orbr{\begin{cases}x+1=8\\x+1=-8\end{cases}\Leftrightarrow\orbr{\begin{cases}x=7\\x=-9\end{cases}}}\)
Vậy