Tìm x biết : x^x+1=x^x
(x mũ x+1 = x mũ x)
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 \(x=4\)
bài 1 : tìm số nguyên x biết : a) (1/16) mũ x = (1/2) mũ 10
b) 3 mũ x 3 mũ x 3 = 756
c) 5 mũ x 1 6 nhân 5 mũ x 1 = 875
tìm x biết: (x-1) mũ x+2=(x-1) mũ x+6
(x-1)x+2 = (x-1)x+6
=> (x-1)x+6-(x-1)x+2=0
=> (x-1)x+2[(x-1)4-1]=0
\(\Rightarrow\orbr{\begin{cases}\left(x-1\right)^2=0\\\left(x-1\right)^4-1=0\end{cases}}\Rightarrow\orbr{\begin{cases}x-1=0\\\left(x-1\right)^4=1\end{cases}}\)
\(\Rightarrow\)x=1 hoặc \(\Rightarrow\orbr{\begin{cases}x-1=1\\x-1=-1\end{cases}}\Rightarrow\orbr{\begin{cases}x=2\\x=0\end{cases}}\)
Vậy \(x\in\left\{1;2;0\right\}\)
tìm x biết: (x-1) mũ x+2=(x-1|) mũ x+6
ta có: \(\left(x-1\right)^{x+2}=\left(x-1\right)^{x+6}\Leftrightarrow\left(x-1\right)^{x+6}-\left(x-1\right)^{x+2}=0\Leftrightarrow\left(x-1\right)^{x+2}\left[\left(x-1\right)^{x+4}-1\right]=0\)
\(\Leftrightarrow[\begin{cases}\left(x-1\right)^{x+2}=0\\\left(x-1\right)^{x+4}-1=0\end{cases}\Leftrightarrow[\begin{cases}x-1=0\\x-1=1\end{cases}\Leftrightarrow[\begin{cases}x=1\\x=0\end{cases}\)
Vậy x = 1 hoặc x = 0
Học tốt nhé ^3^
(x-1)^(x+2)=(x-1)^(x+6)
[(x-1)^x].(x-1)^2=[(x-1)^x].(x-1)^6
(x-1)^2=(x-1)^6
(X-1)^2=(x-1)^2.(x-1)^4
1=(x-1)^4
1=x-1
1+1=x
2=x
Nhớ k cho mình nha
( x - 1 )x + 2 = ( x - 1 )x + 6
\(\Rightarrow\)( x - 1 )x + 2 - ( x - 1 )x + 6 = 0
\(\Rightarrow\)( x - 1 )x . ( x - 1 )2 - ( x - 1 )x . ( x - 1 )6 = 0
\(\Rightarrow\)( x - 1 )x . [ ( x - 1 )2 - ( x - 1 )6 ] = 0
\(\Rightarrow\)( x - 1 )x = 0 hoặc ( x - 1 )2 - ( x - 1 )6 = 0
\(\Rightarrow\)x - 1 = 0 hoặc ( x - 1 )2 - ( x - 1 )6 = 0
\(\Rightarrow\)x = 1 hoặc x = 0
Vậy : x = 1 hoặc x = 0
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 biết :
a, (x+1) + (x+3) +................+ (x+99)=0
b, 1 mũ 3 + 2 mũ 3 +3 mũ 3 +.....................+ 11 mũ 3=(x-1) mũ 2
\(\text{a) ( x + 1 ) + ( x + 3 ) + ..... + ( x + 99 ) = 0}\)
\(\Rightarrow\left(x+x+x+.....+x\right)+\left(1+3+5+....+99\right)=0\)
\(\text{Ta có :}\)
\(1+3+5+...+99=\frac{\left(99-1\right):2+1.\left(99+1\right)}{2}=2500\)
\(\Rightarrow50x+2500=0\)
\(\Rightarrow50x=-2500\)
\(\Rightarrow x=-50\)
Bài 2: Tìm x, biết
a) (x+3) mũ 2 - (x-4)(x+8) = 1
b) (x+3)(x mũ 2 - 3x + 9) -x(x-2)(x+2) = 15
c) (x-2) mũ 2 - (x+3) mũ 2 - 4(x+1) = 5
d) (2x-3)(2x+3) - (x-1) mũ 2 - 3x(x-5) = -44
e) (x-2) mũ 3 - (x-3)(x mũ 2 + 3x + 9) + 6(x+1) mũ 2 = 49
f) 5x(x-3) mũ 2 - 5(x-1) mũ 3 + 15(x+2)(x-2) = 5
g) (x+3) mũ 3 - x(3x+1) mũ 2 + (2x+1)(4x mũ 2 - 2x + 1) - 3x mũ 2 = 42
a) \(\left(x+3\right)^2-\left(x-4\right)\left(x+8\right)=1\)
\(\Leftrightarrow\left(x^2+6x+9\right)-\left(x^2+4x-32\right)-1=0\)
\(\Leftrightarrow2x=-40\)
\(\Rightarrow x=-20\)
b) \(\left(x+3\right)\left(x^2-3x+9\right)-x\left(x-2\right)\left(x+2\right)=15\)
\(\Leftrightarrow x^3+27-x^3+4x=15\)
\(\Leftrightarrow4x=-12\)
\(\Rightarrow x=-3\)
c) \(\left(x-2\right)^2-\left(x+3\right)^2-4\left(x+1\right)=5\)
\(\Leftrightarrow\left(x^2-4x+4\right)-\left(x^2+6x+9\right)-\left(4x+4\right)=5\)
\(\Leftrightarrow-14x=14\)
\(\Rightarrow x=-1\)
d) \(\left(2x-3\right)\left(2x+3\right)-\left(x-1\right)^2-3x\left(x-5\right)=-44\)
\(\Leftrightarrow4x^2-9-\left(x^2-2x+1\right)-\left(3x^2-15x\right)=-44\)
\(\Leftrightarrow17x=-34\)
\(\Rightarrow x=-2\)
e) \(\left(x-2\right)^3-\left(x-3\right)\left(x^2+3x+9\right)+6\left(x+1\right)^2=49\)
\(\Leftrightarrow x^3-6x^2+12x-8-x^3+27+6x^2+12x+6=49\)
\(\Leftrightarrow24x=24\)
\(\Rightarrow x=1\)
f) \(5x\left(x-3\right)^2-5\left(x-1\right)^3+15\left(x+2\right)\left(x-2\right)=5\)
\(\Leftrightarrow5x^3-30x^2+45x-5x^3+15x^2-15x+5+15x^2-60=5\)
\(\Leftrightarrow30x=60\)
\(\Rightarrow x=2\)
g) \(\left(x+3\right)^3-x\left(3x+1\right)^2+\left(2x+1\right)\left(4x^2-2x+1\right)-3x^2=42\)
\(\Leftrightarrow x^3+9x^2+27x+27-9x^3-6x^2-x+8x^3+1-3x^2=42\)
\(\Leftrightarrow26x=14\)
\(\Rightarrow x=\frac{7}{13}\)
Tìm x, biết
a, 3 mũ x + 2 - 5 . 3 mũ x = 36
b, 7.4 mũ x-1 + 4 mũ x+1 = 23
c, 2.2 mũ 2x + 4 mũ 3 . 4 mũ x = 1056
bài 1 : tìm số nguyên x biết :
a) (1/16) mũ x = (1/2) mũ 10
b) 3 mũ x + 3 mũ x+3 = 756
c) 5 mũ x+1 + 6 nhân 5 mũ x+1 = 875